Antimicrobial articles of manufacture

ABSTRACT

Compositions having antimicrobial activity contain surface functionalized particles comprising an inorganic copper salt which has low water solubility. These types of inorganic salts may also be introduced in porous particles to yield antimicrobial compositions. The compositions may optionally comprise additional antimicrobial agents, salts with high water solubility, organic acids, salts of organic acids and their esters. The compositions may be added to various fluids used in the petroleum extraction industry, or used as coatings on components used in this industry. These antimicrobial materials may be used for reducing both anaerobic and aerobic bacteria and are also useful for reducing corrosion of ferrous components caused by anaerobic bacteria. Although such compositions may be used for any antimicrobial application, and some of the other important uses of these compositions are in wound care, personal care and waste processing.

CROSS REFERENCE TO RELATED APPLICATIONS/CLAIMS OF PRIORITY

This application is a continuation of co-pending U.S. application Ser.No. 14/089,146, which is (i) a continuation-in-part of U.S. applicationSer. No. 13/480,367, filed May 24, 2012 (now abandoned), whichapplication in turn claims priority to U.S. Provisional PatentApplication Ser. No. 61/519,523 filed May 24, 2011, U.S. ProvisionalPatent Application Ser. No. 61/582,322 filed Dec. 31, 2011; (ii) acontinuation-in-part of U.S. application Ser. No. 13/685,379 filed onNov. 26, 2015 (now abandoned) which is a continuation in part of U.S.application Ser. No. 13/480,367 (now abandoned); and (iii) which isrelated to and claims priority from U.S. Provisional Patent ApplicationSer. Nos. 61/800,122 filed on Mar. 15, 2013; 61/820,561 filed on May 7,2013, and 61/881,318 filed on Sep. 23, 2013. The contents of all of theforegoing applications are incorporated herein by reference entirely.

FIELD OF THE INVENTION

The invention relates to antimicrobial compositions comprising surfacefunctionalized particles of low water solubility inorganic copper salts,or such copper salts or silver salts infused into porous particles,their preparation, combinations of these copper-based particles withother antimicrobial materials, application of the compositions andmethods of preparation.

BACKGROUND OF THE INVENTION

The antimicrobial effect of various metals and their salts has beenknown for centuries. Its germicidal effects increased its value inutensils and as jewelry. The exact process of silver's germicidal effectis still not entirely understood, although theories exist. One of theseis the “oligodynamic effect,” which qualitatively explains the effect onsome microorganisms, but cannot explain antiviral effects. Silver iswidely used in topical gels and impregnated into bandages because of itswide-spectrum antimicrobial activity.

The oligodynamic effect is demonstrated by other metals, specificallygold, silver, copper, zinc, and bismuth. Copper is one such metal.Copper has long been used as a biostatic surface to line the bottoms ofships to protect against barnacles and mussels. It was originally usedin pure form, but has since been superseded by brass and other alloysdue to their lower cost and higher durability. Bacteria will not grow ona copper surface because it is biostatic. Copper alloys have becomeimportant netting materials in the aquaculture industry for the factthat they are antimicrobial and prevent biofouling and have strongstructural and corrosion-resistant properties in marine environments.Organic compounds of copper are useful for preventing fouling of ships'hulls. Copper alloy touch surfaces have recently been investigated asantimicrobial surfaces in hospitals for decreasing transmission ofnosocomial infections.

Numerous scientific investigations have focused on the role of the metalform of copper, and have concluded that multiple mechanisms may bepossible for copper's antimicrobial effect, including increasedproduction of reactive oxidation species such as singlet oxygen andhydroxide radicals, covalent binding of copper metal to reactive sitesin enzymes and co-factors, interference with lipid bilayer transportproteins, and interaction of copper ions with moieties of microorganismsanalogous to what have been proposed for silver ions.

SUMMARY OF THE INVENTION

The inventors associated with this patent have made the surprisingdiscovery that antimicrobial compositions comprising particlescomprising certain low water solubility copper salts have much greaterefficacy against a broad range of aerobic and anaerobic microbes,including bacteria, viruses, molds and fungi, than similar silver-basedantimicrobial particles. In particular, it has been discovered thatparticles of copper salts including the copper halide and specificallycopper iodide (“CuI”), when formulated in accordance with the teachingsherein, is surprisingly effective as a broad-spectrum, fast-actingantimicrobial agent. The particles of these salts are surfacefunctionalized.

In a further embodiment, high water solubility salts may be added to thecompositions comprising the inventive particles. In a particularlypreferred embodiment, the high water solubility salts comprise at leastone halide salt with a room temperature water solubility of greater than1 g/liter.

In yet another embodiment, organic acids, salts of organic acids, andesters of organic acids may be used as functionalization agents for theparticles or as additives to the antimicrobial compositions.

In yet another embodiment, the antimicrobial compositions of thisinvention may be used to manufacture solid or liquid products withantimicrobial properties.

In a further embodiment, the functionlization agents preferably have amolecular weight of at least 60.

In yet another embodiment, the antimicrobial compositions are used inthe petroleum extraction industry, personal care products and woundmanagement.

Another embodiment of the present invention is the use of the aboveantimicrobial compositions is to kill anaerobic as well as aerobicbacteria.

In yet another surprising discovery, the preparation of the inventiveparticles using wet grinding processes enhances their economic viabilityand provides several other benefits. Such processes may be used toproduce functionalized particles of other low water solubility salts andcompounds such as silver halides.

In a further embodiment, one may deposit the copper salts of low watersolubility or silver halides in porous particles, wherein such porousparticles are used as additives to various carriers (liquids or solids)or products to impart antimicrobial properties to these.

These and other features of the present invention will become apparentfrom the following detailed description and the accompanying drawings

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plot of Optical Density (OD, Y-axis) against P. aeruginosagrowth and/or inhibition by copper iodide particles and Ag—CuI mixedmetal halides, and a control.

FIG. 2 is a plot of Optical Density (OD, Y-axis) against S. aureusgrowth and/or inhibition by copper iodide particles and Ag—CuI mixedmetal halides, and a control.

FIG. 3 is a bar chart showing the effectiveness of CuI against thegrowth of Bacillus cereus spores.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 1. Introduction

The present invention is concerned broadly with compositions andparticles of oligodynamic metals and their compounds, and withcombinations of such compositions and particles with other knownantimicrobials. These compositions may be added to articles ofmanufacture which result in antimicrobial products. These productsinclude liquids and solids, wherein the solids include coatings. Theinventors associated with this patent have made the surprising discoverythat particles made of certain metal salts have much greater efficacyagainst a broad range of bacteria, viruses, molds and fungi than knownsilver-only based antimicrobial particles. In particular, it has beendiscovered that the copper halide salt, copper iodide (“CuI”), whenformulated in accordance with the teachings herein, is surprisinglyeffective as a broad-spectrum, fast-acting antimicrobial agent.Therefore, a first embodiment of the invention is directed to acomposition having antimicrobial activity comprising a particlecomprising at least one inorganic copper salt, the particle preferablyhaving an average size of less than about 1000 nm; and at least onefunctionalizing agent in contact with the particle, the functionalizingagent stabilizing the particles in a carrier such that anantimicrobially effective amount of ions are released into the environsof the microbe.

2. The Compositions and Processing

a. Oligodynamic Metals

In one embodiment of the invention, the preferred material compositionscomprise at least one metal halide and the combination of one or moremetals with at least one metal halide. Preferred metals are copper,zinc, silver and their alloys, and preferred metal halides are copperhalides, and silver halides, especially copper iodide, copper (l)chloride, silver iodide, silver bromide and silver chloride. Example ofthese alloys are those of silver+copper, copper+tin (bronze) andcopper+zinc (brass is an alloy of copper and zinc with typical copperconcentrations in the range of 40 to 90% by weight, and may haveadditional elements, e.g., as in phosphor bronze). These alloys mayprovide better stability of particles in the processing or in end useapplications against oxidation or non-desirable surface reactions. Inmost cases, the material compositions of this invention are preferablyadded into articles or products as preformed particles. That is, thesurface functionalized salt particles are formed before they are addedto the end-product or the formulation used to make the end-product.Similarly, porous particles with antimicrobial materials deposited intothe pores are preformed prior to their incorporation in the end-productor the formulation used to make the end-product. The functionalized saltparticles or the porous particles may undergo additional chemical orphysical reactions once they are added to the end-product or theformulation used to make the end-product.

b. Copper Salts

The copper salt embodiments of the present invention include coppersalts, both inorganic and organic copper salts. By way ofexemplification the following copper compounds are illustrative but notlimiting: Copper(II) iodate; Copper(I) iodide; Copper(I) chloride;Copper(I) bromide; Copper(I) oxide; Copper(I) acetate; Copper(I)sulfide; and Copper(I) thiocyanate.

The copper salts may have a range of water solubility characteristics.However, it is preferred that the copper salts of the present inventionhave low water solubility so that they may have slow and predictablecopper cation release characteristics. In some formulations it may bedesirable to also add Cu(II) or more soluble salts so that some fractionof Cu ions are quickly available. Cu(I) cations have shown the mostefficacy against the various microbes tested. At room temperature,copper salt solubilities of less than about 100 mg/liter are preferred,and more preferred are copper salts having water solubilities less thanabout 15 mg/liter. In many applications lower water solubility isimportant, particularly where antimicrobial products come in contactwith body fluids and water and long term efficacy is required. In somecases metal salts with high water solubility are added as additionalantimicrobial agents so as to release a high concentration of ions overa short period of time. In addition, the human body also regulates theconcentrations of several elements (labeled as micronutrients).Interestingly both elements of copper iodide, i.e., copper and iodine,belong to this class of elements. On the one hand, the low solubility ofcopper iodide allows one to make products with high efficacy where suchefficacy is retained for a long time, and further, due to bodyregulative functions it is also not toxic at the levels at which it isan effective antimicrobial agent.

Other embodiments of copper (I) salts that may be useful in the presentinvention include halides where some of the copper has been substitutedwith other cations which may be other metals (forming mixed halidematerials), or a given halide may be substituted with other anions.Alternatively, the substitution may be organic in nature, examples ofsuch substitutions include e.g., AgCuI₂, CH₃NCuI₂, Rb₃Cu₇Cl₁₀, RbCu₃Cl₄,CsCu₉I₁₀, CsCu₉Br₁₀, Rb₄Cu₁₆I₇Cl₁₃ and RbCu₄Cl₃I₂. In general one mayexpress these mixed halide copper salts as P_(s)Cu_(t)X_((s+t)), where Pis the organic or a metal cation and X is a halide, preferably selectedfrom one or more of Cl, Br and I. An alternative way to express thesecompositions is P_(s)Cu_(t)X when t=1−s.

c. Copper Halides

Halide salts are particularly preferred, since in addition to the copperions, these salts also contain anions which have antimicrobial affects.For example, chlorine, bromine and iodine ions are used as antimicrobialagents in several cleaning and medical applications. Copper iodide(CuI), like most “binary” (containing only two elements) metal halides,is an inorganic material and forms a zinc blende crystal latticestructure. It can be formed from a simple substitution reaction in waterwith copper acetate and sodium or potassium iodide. The product, CuI,simply precipitates out of solution since it is sparingly soluble (0.020mg/100 mL at 20° C.) in water. Copper iodide powder can be purchased inbulk from numerous vendors. For medicinal or human applications, gradewith over 98% purity is particularly preferred.

Copper bromide (CuBr) is also an inorganic material having the samecrystal structure as CuI. It is commonly prepared by the reduction ofcupric salts with sulfite in the presence of bromideCuBr is alsosparingly soluble in water but has asolubility greater than that of CuI.Further, as discussed below for many applications, on the basis ofcoloration, CuBr is less preferred as its powder has a lower L* value.

Copper chloride shares the same crystal structure with CuBr and CuI andhas a solubility of 62 mg/100 mL.

Copper(I) fluoride disproportionates immediately into Cu(II) fluorideunless it is stabilized by complexation, so CuF is not a very usefulcopper halide particle source. Cu(II) fluoride is soluble in water andso it is not a source of Cu(I) cations, but is a source of Cu(II)cations.

For many (but not all) applications, the appearance and color of thecoatings or the bulk products is important. For these applications theantimicrobial material should not change the appearance significantly.Some examples of these are paints and varnishes for buildings, fixturesand furniture, coatings for cosmetics use, incorporation in moldedarticles, and coatings and bulk incorporation in fibers for textiles,carpets, gaskets, etc. Thus it is preferred that the additives arecolorless or pale in color and do not change the coloration of theproduct significantly after they are added. For many applications thecoloration of these materials may be assessed by looking at the color ofbulk powders. In general for applications where appearance is important,the color of the bulk powder should preferably meet certain requirementsas discussed in the next section relating to the L*a*b* colorcoordinates.

d. Non-Copper Salts

In addition to being antimicrobial, preferred metal salts have low watersolubility (less than 100 mg/liter or more preferably less than 15mg/liter at 25° C.). When low water solubility antimicrobial materialsare added to coatings or bulk materials, they provide an efficacy thatlasts for long periods. The materials of the present invention may becombined with other antimicrobials in a product. These otherantimicrobials may include salts with greater water solubility and evenwater-soluble salts in cases where one wants to provide a quick as wellas a sustained antimicrobial efficacy, or if they perform some otherfunction in the formulation.

Besides low water solubility, there are also other desirable attributesof the materials which may be important for specific applications. Theseinclude the colorless or weakly colored materials, stability inatmosphere, and stability to temperature for both processing and in use.Table 1 shows water solubility of a few select metal halides and othersalts.

TABLE 1 Water solubility of selected metal salts at room temperatureMaterial Water solubility (mg/L) AgI 2.2E−03 AgBr 1.4E−01 AgCl 1.9E+00CuBr 1.1E+01 CuI 2.2E−01 CuCl₂ 7.0E+05 CuCl 6.2E+01 CuSCN 8.4E−03 ZnI₂4.5E+06 ZnBr₂ 4.5E+06 ZnCl₂ 4.3E+06 BiI₃ 7.8E+00

Table 2 shows the color coordinates of various copper, silver and someother halides. The color coordinates of various powders were measured onthe Colorimeter model UltraScan XE (from Hunterlab, Reston, Va.) in RSINreflectance mode using the small, 0.375 inch aperture. A glass slide wascovered with a piece of double sided tape and a small amount of thepowder as received from Sigma Aldrich was placed on the double sidedtape to give a smooth, solid dry powder finish. To protect the powderfrom disengaging into the colorimeter while the measurements were beingperformed, a second slide (top slide) was then placed over the top ofthe first and the two slides were taped together. The double slide wasthen read for L*a*b* coordinates on the colorimeter with the top slidefacing the reflectance port.

The colors measured here are not absolute values for a given material,as the color also depends on the level of purity and the type ofimpurity present in these materials. An L* value of 100 (maximum)indicates a completely white color and a value of 0 indicates acompletely black color. For a low degree of color, the color of the bulkpowder should preferably have a L* value greater than 65, and morepreferably greater than 70, and most preferably greater than 80 whenmeasured on a color scale of L*a*b*. The desirable values of a* and b*are dependent on L* value, and should be as close to zero as possible.As a rough guideline, when L* value is at 65, the a* and the b* valuesare preferably within ±5, when L* value is at 70, the a* and the b*values are preferably within ±15, when L* value is at 75, the a* and theb* values are preferably within ±20, and when L* value is at 80 orgreater, the a* and the b* values are preferably within ±25 as long asthese values are within the L*a*b* color sphere. Color may also bemeasured for functionalized particles in dry powdered state, and it isalso preferred that such powders exhibit low coloration along the aboveestablished guidelines.

TABLE 2 Color coordinates of as received powders Source, CatalogueMaterial number L* a* b* BISMUTH (III) Sigma Aldrich, 341010 0.01 0.090.02 IODIDE GOLD (I) IODIDE Sigma Aldrich, 398411 76.6 −1.98 34.55SILVER BROMIDE Sigma Aldrich, 226815 45.02 −20.55 42.49 SILVER IODIDESigma Aldrich, 204404 78.05 −7.13 20.28 SILVER CHLORIDE Sigma Aldrich,227927 72.46 4.01 5.05 COPPER Sigma Aldrich, 254185 42.02 −29.36 −3.45(I)BROMIDE COPPER (I) Sigma Aldrich, 205540 72 2.54 10.85 IODIDE COPPER(I) Sigma Aldrich, 229628 76.35 −4.46 14.93 CHLORIDE COPPER (I) SigmaAldrich, 298212 76.17 0.46 8.79 THIOCYANATE

These indicated color characteristics are required so that theappearance of the product incorporating the functionalized antimicrobialparticles (e.g., coatings molded products, fibers) is not compromised.Color is less important for those applications where appearance is notan issue or where the articles already have a strong color.

Temperature stability is dependent on the processing temperature used toproduce the product and the temperature seen during the use. Sinceantimicrobial materials have to go through a long regulatory process, itis difficult to change composition for each application; thus it isdesirable that a given composition can be used over a broad range ofconditions. Since most molding operations for polymers, including powdercoating operations, are carried out at temperatures ranging from about150 to about 250° C., it is preferable for the compositions to be stableto 150° C. or higher. Since the melting points of nanoparticles in asize smaller than 50-100 nm may be significantly lower than those ofbulk materials, the melting point must be notably higher than theexpected use temperatures when particles smaller than 50-100 nm areused. The preferred non-copper salts of oligodynamic metals are those ofsilver. Of these the more preferred salts are silver halides, and inparticular AgCl, AgBr and AgI. Of these AgCl and AgI are more preferreddue to lower degree of coloration (higher L* value), particularly forthose applications where color of the product is important.

Further, the preferred silver halides also have a drawback in that thematerials tend to exhibit coloration to light such as the sun. Hence forthose products where exposure to light such as sunlight is anticipated,these halides may desirably be doped with other materials so as toreduce the darkening. One way of accomplishing this is to make compoundssuch as mixed metal halides (or doping one metal halide with anothermetal halide) to reduce discoloration but still preserve low color, lowwater solubility and other desirable attributes. Another approachinvolves silver halide particles with mixed anions. Additional aspectsof mixed metal halides are also discussed in the section below. Yetanother approach is to make compostions when functionalization agentsare materials with strong UV absorption, or even visible radiation (aslong as it does not impair the product characteristics) so that theyabsorb a significant amount of radiation to reduce the impact ofradiation on the metal halides.

It should be noted that while some of the copper halides may alsoexhibit mild discoloration on exposure to light such as sunlight, theextent of such discoloration is markedly less than that of the silverhalides, and any such discoloration which can also be reduced by doping.

In addition, attractive economics of the material are also veryimportant for a variety of applications. The cost of copper compounds,such as the preferred copper halides of the present invention, isnotably smaller than that of silver compounds. When the functionalizedantimicrobial materials of the present invention comprise silverconstituents, it is preferred to minimize the extent of such additionsof silver constituents consistent with achieving the desiredantimicrobial efficacy and other desirable attributes.

Other metal iodides may also be used, in conjunction with the materialsof this invention, but many of the metal halides have drawbacks whichlimit that usefulness in many applications as primary antimicrobialagents. A few select iodides with their principal shortcomings are;germanium (II) iodide (decomposes at 240° C.); germanium(IV) iodide(melting point is 144° C.); tin(II) iodide (is bright red in color);tin(IV) iodide (red in color and hydrolyses in water);platinum(II)iodide (black in color); bismuth(III) iodide (black incolor); gold(I) iodide (unstable, decomposes on treating with hotwater); iron(II) iodide (black colored and water soluble); cobalt(II)iodide (black colored and water soluble); nickel(II) iodide (blackcolored and water soluble); zinc(II) iodide (white colored but watersoluble); and indium(III) iodide (orange colored). As seen, theseiodides are deeply colored, or have low melting point or poor thermalstability, poor stability when exposed to oxygen or moisture, or highwater solubility. These or other metal iodides may, however, be used tomix or dope the desirable copper or silver halides as long as thedesirable properties of these materials are not compromised.

e. Mixed-Metal Halides

Further embodiments of the invention are directed to mixed-metalhalides. These are novel halide salts containing more than a singlecation, or containing more than a single anion or containing more than asingle cation and more than a single anion. In the mixed-metal halidesof the present invention, at least one of the cations is an oligodynamicmetal cation, preferably a copper cation. More preferably, all of themixed-metal cations are oligodynamic metal cations. Embodiments includesilver-copper halide, gold-copper halide, silver-gold halide, etc. Forexample a metal halide of two metals with a common anion may beexpressed as M₁-M₂(X), where M₁ is the first metal, M₂ is the secondmetal and X is the halide anion. Another combination is M₁-M₂(X₁-X₂),where X₁ and X₂ are different halogen anions. Most preferred embodimentsinclude silver-copper halides. Embodiments may include halogens such asiodide, bromide and chloride. A preferred embodiment is Iodide. Someexemplary embodiments are (Cu—Ag)I, (Cu—Ag)Cl, (Cu—Ag)(Br—I),(Cu—Ag)(I—Cl), Ag(Cl—I) and Cu(Cl—I). Please note that thestoichiometric proportion in the mixed metal halides between the variousanion and the cations may be any which can be formed and is suitable forthe application. In one embodiment, the particles preferably have morethan 21% by weight of copper salts with a solubility of less than 100mg/liter; more preferably the particles should have more than 51% byweight of such copper salts and most preferably these salts should beabout more than 71% by weight.

f. Mixtures of Particles

In other embodiments of the present invention, the functionalizedparticles comprise mixtures or combinations of functionalized particlesof different compositions wherein at least one component arefunctionalized particles of a salt of oligodynamic metals. In a specificembodiment, compositions comprising copper halide particles especiallycopper iodide may be combined with silver halides particles, e.g.,silver bromide. In a further embodiment, these compositions,particularly compositions comprising copper halides especially copperiodide may be combined with other known antimicrobial or antifungalagents. One may also combine particles of differentsizes/composition/solubilities to control the delivery rate and thelongevity of the antimicrobial efficacy of the products in which wheresuch particles are incorporated. As an example, one may combineparticles about 300 nm in size with those that are less than 30 nm, orone may combine particles larger than 300 nm in size with those that aresmaller than 300 nm, etc.

In applications such as those where copper or other compounds are usedfor antimicrobial effects, one may combine those materials withmaterials of the present invention. As a specific example, in marinecoatings where zinc pyrithione, cuprous oxide or copper thiocyanate areused for their antimicrobial properties, one may prepare these compoundsas functionalized particles with sizes smaller than about 300 nm. Asanother specific example, these materials may be combined with copperiodide as taught in the present invention. As another specific example,one may also use other antimicrobial compounds which are relativelywater soluble in conjunction with the materials of the presentinvention. In such cases, the more water soluble component will resultin a fast release of antimicrobial ions when such products are broughtin contact with moisture. Some examples are, silver nitrate, copper (II)chloride, zinc chloride, potassium iodide, sodium iodide and zinciodide.

Embodiments of the mixture of particles are directed to a compositionhaving antimicrobial activity comprising (a) a mixture of particlescomprising particles of a copper salt and particles of at least a secondinorganic metal compound or metal; and (b) at least one functionalizingagent in contact with at least one of these particles. A furtherembodiment of the copper salt comprises a copper halide salt, and astill further embodiment of the copper salt comprises copper iodide. Oneof the preferred materials for use as second metal is silver and thepreferred compounds are silver halides.

For many applications cost is an important issue. Addition of preciousmetals or their salts to the compositions of this invention can makeantimicrobial materials less attractive economically. Since the coppersalts of the present invention have shown high efficacy against avariety of microbes and are less costly than the silver halides, formany applications mixing copper halides with silver, gold, platinum orother precious metals and their salts is not necessary. If needed forspecific applications, the precious metals and their salts may beutilized in much lower concentrations than if they were not combinedwith the copper salts.

g. Functionalizing Agents

An important embodiment of the present invention is thefunctionalization of the metal salt particles. In functionalizing thesurfaces of the particles of oligodynamic metals and their compounds orsalts, a number of chemical species may effectively be used, which maybe selected from one or more of the categories below. Thesefunctionalizing agents are preferably present while the particles or newsurfaces are being formed, either during chemical synthesis, or duringphysical grinding when they are being ground to a finer size from largerparticles. The amount of surface functionalizing agent increases withdecreasing particle size in proportion to the overall change in surfacearea exposed for functionalizing. Any ratio of the relative amounts ofthe metal salt particles and the functionalizing material may be used,typically these are present in a weight or a molar ratio (metalsalt:functionalizing agent) in a range of about 100:1 to about 1:100 andmore preferably a range of about 20:1 to 1:20. For polymericfunctionalization agents, the molarity is calculated based on averagemolecular weight of a repeat unit in a polymer chain rather than themolecular weight of the entire polymeric chain. For a specific metalsalt and functionalization agent either weight ratio or molar ratio maybe used whichever ratio results in larger range. When the organicfunctionalizing agents are employed, their molecular weight shouldpreferably be greater than 60. One purpose of the functionalizing agentsis to reduce the interparticle interaction so that they disperse moreeasily. Putting higher molecular weight functionalization agents helpsto weaken this interaction between the particles and helps dispersion.

Surface functionalization typically imparts one or more of manyattributes, such as preventing particles from agglomeration (e.g.,promoting suspension stability, particularly in liquid products and inliquid coating formulations), enabling particles to attach to varioussurfaces of an object or even to the microbes or the interior of themicrobes, assisting antimicrobial materials to penetrate the membrane ofthe microbes and assisting particles to attach to matrix materials whenthese are incorporated as composites into other materials. Thisfunctionalization also helps to disperse the antimicrobial particleseasily into these matrices (e.g., blending with thermoset orthermoplastic polymers which are later molded into objects). Thefunctionalization may also assist in transporting these particles and/orthe ions generated from them through the microbe outer layers, orthrough the matrices they are incorporated into. The functionalizationmay also assist in keeping the physical and chemical properties of theproduct in which the particles are incorporated from changing in a waythat is undesirable.

Several functionalization agents are taught in this section, and manymore are taught later in various sections including applicationssection. It must be understood that any of the functionalization agentlisted in this invention may be used for any antimicrobial applicationand must not be limited by specific examples in which they arediscussed.

Use of acids along with other surface functionalization agents or otherfunctionalization agents with mildly reducing properties are desirablewhen Cu(I) halides (e.g., CuI, CuBr, CuCl) are used as antimicrobialmaterials. In the presence of or in association with these materials Cu⁺ions are prevented from oxidizing to Cu⁺⁺ ions. This is desirablebecause Cu⁺ have superior antimicrobial properties. Examples of acidsinclude mineral acids (e.g., hydrochloric acid, nitric acid, sulfuricacid), or organic acids (such as acetic acid, ascorbic acid, citricacid, glutamic acid, sorbic acid, erythorbic acid, thiodipropionic acid,sulfamic acid, adipic acid, gallic acid, alginic acid, caprylic acid,linoleic acid, cinammic acid and alkylbenzene sulfonic acids such asdodecyl benzene sulfonic acid). Examples of reducing agents includealcohols, polyols and aldehydes of the organic materials listed above,and some specific examples also include sugars, glucose, xylitol,sorbose, cinnamonaldehyde, etc.

Salts of many of the above acids (particularly containing cations oflithium, sodium potassium, calcium, zinc and copper) and esters oforganic salts of the above acids may also be used and may be combinedwith additional functionalization agents. Some examples of alkali saltsof the above salts are mono, di and tri-sodium citrates, sodiumascorbate, sodium sorbate, sodium iodide, sodium cinnamonate, etc. Inaddition to sodium some of the other preferred alkali ions are lithiumand potassium. Similarly one may use salts of the other mentionedcations. Some other examples of preferred salts are copper citrate,halides of lithium, sodium and potassium, sodium palmitate, sodiumoleate, sodium formate, calcium diacetate, sodium gluconate, sodiumcarboxy methyl cellulose, sodium caseinate, zinc gluconate and zincstearate. These salts stabilize the Cu⁺ ions and act as buffers tomaintain the pH in a desired range. Some examples of esters of theorganic acids are lauryl gallate and ascorbic acid palmitate. Laurylgallate and ascorbic acid palmitate have low water solubility, and thusmay be more suitable for non-aqueous formulations. One has to be carefulin using excess acids as they may themselves act as antimicrobialagents, and may also reduce Cu⁺ to Cu^(o) which may impart undesirablecolor or even cause precipitation. These salts or alcohols, polyols andaldehydes of the organic materials listed above may be used as additivesto the antimicrobial compositions, wherein the same or differentmaterials may be used as functionalization agents.

Incorporation of soluble salts in the compositions of this invention mayimpart additional attributes. Some examples of soluble salts includehalides and non-halides. As another example, when copper or silveriodide is used, the use of lithium iodide, sodium iodide and potassiumiodide along with poly vinyl pyrrolidone and its copolymers promotedispersability, and it is likely that some of these salts form a complexwith the polymer to produce a composite which is a more efficientsurface functionalization agent.

Further, one may also incorporate materials in their elemental form,e.g., metals and nonmetals into the compositions. If such materials areincorporated preferably they should be less than 5% by weight (based onthe weight of the metal salts which are being functionalized), and morepreferably less than about 2%.

Functionalization agents may also provide other useful functions to aformulation. As an example, the functionalization agents may also beantimicrobial materials (such as many cationic surfactants, phenoxyethanol, 1-2 octane diol, etc.), may have UV stabilization (and/or UVabsorption) properties (e.g., benzophenones, benzotriazoles, acrylicesters and triazines) which would reduce photochromic orphotooxidadtion, may also have antioxidant properties as discussedearlier (e.g., ascorbic acid, butylated hydroxytoluene, furanones) andmay be polymerization initiators (including photoinitiators) or dyes toimpart superior polymerization characteristics to the monomerformulations trhese are added to or certaincolors or fluorescenceproperties. In addition to UV stabilization, benzotriazole is also knownto prevent oxidation of metals. One may add more than one of the surfacefunctionalizing agents with different attributes. This allows productsto be made economically with low added cost. As discussed later, some ofthe processing technologies disclosed herein are particularly suitablefor achieving this in a facile way.

Besides providing outstanding antimicrobial properties, functionalizedcuprous iodide by itself or in combination with cuprous bromide and/orsodium or potassium iodide can also be used to promote thermal stabilityof some polymers (e.g., nylons). For achieving both the thermal andantimicrobial properties the level of addition of copper iodidefunctionalized particles in bulk polymers should preferably be at least0.05% by weight of the polymeric formulation and more preferably be atleast about 0.1% (but still less than 5% in both cases).

Well dispersed finer particles in liquids or solids (including coatings)result in a more uniform distribution of the particles in the bulkmaterial or on the coated surface and more of the surfaces of theseparticles is available to interact with the microbes. For particles thatare a few nanometers in size, the surface functionalization can alsoinfluence their transportation into the interior of the microbes, suchas penetration through the lipid layers. Functionalizing agents that mayfacilitate transport of nanoparticles to the surface of a microbeinclude surfactants, amino acids and combinations of amino acids and/orsurfactants with peptides, polypeptides and carbohydrates. It was foundthat when certain embodiments of amino acids are used to functionalizethe surfaces of the oligodynamic metal-containing nanoparticles,enhanced antimicrobial activity was obtained. Use of properfunctionalization agents may also facilitate the transportation of theparticles to the interior of biofilms so that the embedded microbes canbe destroyed.

Amino acids which are preferred as amino acid functionalizing agents forthe present nanoparticles include aspartic acid, leucine and lysine,although numerous other amino acids can also have efficacy. Also usefulare combinations of amino acids, dipeptides, tripeptides andpolypeptides. Other embodiments of functionalizing agents includecarbohydrates such as mono- and di-saccharides and their derivatives,enzymes, glycols and alcoholic esters (e.g., Schercemol™ and Hydramol™esters from Lubrizol (Wickliffe, Ohio)). Some of the polypeptides mayalso enhance the transport of the antimicrobial materials of thisinvention through the membrane of the microbes. Of the surfactants,anionic or non ionic surfactants are preferred.

Other embodiments of the invention are directed to various polymers thatmay be used for functionalization. Typically the functionalizationprocedure is done in a liquid medium in which these polymers are presentin a solution and/or an emulsion form. Polyvinylpyrollidone and itscopolymers represent one embodiment that can be an effective agent formodifying the surface chemistry of the antimicrobial particles. Examplesof other polymeric surface modifiers include polyacrylic acid,copolymers comprising acrylic (including methacrylic acid) groups,soluble cellulosics (e.g., carboxy methyl cellulose), polyacrylamide,polyethylene and polypropylene glycols or oxides (and their copolymers),polyolefins modified with maleic anhydride (e.g., OREVAC® polymers fromArkema Group, King of Prussia, Pa.) polymers with alcoholic groups,urethanes, epoxies and carbohydrate polymers. As taught in severalplaces in this specification, block and graft (including comb likepolymers) copolymers are suitable under a variety of circumstances asthey can provide good compatibility and dispersion characteristics. Eachof the above polymers may have a range of molecular weights, typicallyin the range of about 1,500 and 1,000,000 Daltons, although molecularweights less than 200,000 are preferred, and molecular weights less than25,000 are most preferred. Useful functionalizing polymers may also becombined with several of the other functionalization agents mentioned inthis specification. Typically at least one of the functionalizationagent has a minimum molecular weight of 60. Solubility and solutionviscosity of the polymer generally correlates with average molecularweight, with high molecular weights being less soluble in water andresulting in more viscous solutions. When using block or graftcopolymers, one may advantageously use those materials where sections inthe copolymer have different properties in terms of ioniccharacteristics or their attraction/compatibility with water. Forexample, one block or graft may be hydrophobic or ionic, and anotherblock or another graft or the main polymer chain may be hydrophilic ornon-ionic, etc.

Another embodiment of functionalizing agents includes mercapto and thiolfunctionalizing agents in addition to the above-cited functionalizingagents. Thiol modifying agents useful for functionalizing theantimicrobial nanoparticles include aminothiol, thioglycerol,thioglycine, thiolactic acid, thiomalic acid, thiooctic acid andthiosilane. Combinations of thiol modifying agents can also be used inthe present invention.

The functionalization of the particles may also provide additionalattributes desirable for using them in practical applications. Theseattributes include the promotion of adhesion of the particles to and/orreaction of the particles with specific matrices such as in bulkmaterials and coatings and the enhancement of their antimicrobialproperties by making the interaction between particles and microbes moreattractive or by coupling or combining them with other materials forspecific applications. Examples of other materials with which thepresent antimicrobial particles can be combined include antimicrobialagents which target a specific microbe or group of microbes, ormaterials that under illumination or humid or anaerobic conditionsprovide modified antimicrobial activity. The surface functionalizationagents may also help disperse these particles in polymers, and for thatpurpose one may employ typical processing aids which are used in suchapplications. Some examples are stearic acid and their esters and salts(also see discussion on surfactants).

Examples of coupling agents and monomers for increasing thecompatibility of the antimicrobial particles with various polymericmatrices include organosilanes (e.g., epoxy silanes for use in epoxymatrices, mercapto silanes for use in urethane and nylon matrices,acrylic, methacrylic and vinyl silanes for use in reactive polyester andacrylic polymers). Other monomers include those materials which have theability to attach to the surfaces of the particles and also react orbond with matrices into which such modified particles are introduced.Some examples include polyolys (e.g. diols), silanes (includes silanatedquats), metal alkoxides, acrylic polyols, methacrylic polyols, glycidylester acrylics and methacrylics.

Metal alkoxides and other metal oxide precursors (e.g., metallo-organic,water soluble silicate, aluminate, titanate and zirconate, mixed metalprecursors such as alkoxy aluminum silicates, etc) may be used tofunctionalize the particles with layers of porous oxides containingmaterials. Some of the preferred materials contain silica, titania,alumina, zirconia, zinc and mixtures of these. In such cases, M₁-O-M₂bonds are formed, where M₁ and M₂ may be different or the same metalsand “O” represents oxygen. Such compositions may also include aproportion of monovalent and divalent metals such as sodium, potassium,calcium, barium, and magnesium to change the density (porosity) of theresulting oxides and their surface properties. There may also includeresidual organic groups from the precursors. These compositions may alsocontain organic reactive precursors, particularly hydrophilic precursorssuch as polyethylene oxide (molecular weight of about 200 to 10,000) toproduce networks which are more open or with tailoredporosity/hydropillicity.

Some specific examples of metal alkoxides includetetraethylorthosilicate, tetramethylorthosilicate, titaniumisopropoxide, aluminum isopropoxide, aluminum butoxide, zirconiumethoxide; and some specific examples of water soluble silicates includesodium silicate and potassium silicate. In some cases, more than oneoxide composition may be used so that a first composition is used tomodify the surface of the antimicrobial particles, and then a second ora subsequent composition is used to modify the surface of the firstcomposition. This can assist in tailoring not only the porosity of themultilayer compositions, but also the final isoelectroc points/chemistryso that the particles can be tailored to be compatible with any desiredmatrix.

A judiciously selected surface functionalization of this type canprotect the particles from undesired interactions with theirenvironments. This protection helps to maintain the particle integrityin environments where the chemical and/or physical composition of theparticles may be degraded in absence of such protection. By tailoringthe chemistry and the porosity of these functionalization layers, it isalso possible to control the release rate of the antimicrobially-activespecies from the particles.

Embodiments of the invention also make use of surfactants for surfacemodification. The term surfactants would mean nonionic, cationic,anionic and amphoteric surfactants, some specific examples being Brij,Tween (polysorbate), Triton X-100, benzethonium, benzalkonium,dimethyldialkylonium, alkylpyridinium and alkyltrimethylammonium cationswith any anion, e.g., bromide, chloride, acetate or methyl sulfate,silicone-ethylene oxide/propylene oxide copolymers (e.g., OFX-0190,OFX-0193 and OFX-5329 from Dow Corning, Midland, Mich.), Sodium dodecylsulfate (SDS), sodium capryl sulfonate, sodium lauryl sulfate, sodiumlaureth sulfate, cetyltrimethylammonium chloride orcetyltrimethylammonium bromide (all available from Sigma-Aldrich Co,Milwaukee, Wis.), silicone surfactants, fluorosurfactants (e.g., Novecsurfactants from 3M (St. Paul, Minn.) such as FC-4430, FC-4432, FC-4434and FC-5120), salts of organic acids. Some others are fatty alcoholethoxylates, alkyl phenol athoxylates, phosphate esters, acetylene diols(e.g., ethoxylated acetylene diols), salts of polyacrylic acid (e.g.,sodium salts of polyacrylic acid) and soy lecithin. Anionic, amphotericand nonionic surfactants are preferred, and anionic and non-ionicsurfactants are most preferred.

One may also use surfactants (including emulsifiers) to form emulsions(including latex) of polymers and other materials, wherein suchemulsions are used to modify the surfaces of the particles. For thispurpose the polymers may be hydrophobic. Some examples includepolyurethane emulsions, acrylic emulsions, fluorosilicone emulsions andepoxy emulsions. This method is particularly suitable wherenanoparticles are made by grinding of larger particles of theantimicrobial materials in a liquid comprising a polymeric emulsion. Thenanoparticles formed are functionalized by this emulsion. Alternativelyone may grind the AM material in presence of a surfactant and then addthis to the polymeric emulsion. Optionally, the functionalized particlesmay be dried as a powder and then added to the polymeric emulsion.

For oil based paints, one may use a variety of oil based surfacemodifiers, which may be easily incorporated on the surfaces of theparticles by grinding. These may selected from different drying oilssuch as linseed oil, common industrial oil belonging to the class ofpolyunsaturated fatty acids. The viscosity of the grinding medium andother attributes may be controlled by adding solvents such as toluene,turpentine and white spirit. For some applications, particularly inpreparing functionalized antimicrobial particles for cosmetic andpersonal care (body care) or for other uses, one may also use oils andextracts for surface modification derived from natural sources orsynthetic methods. These may also impart additional antimicrobialproperties such as oils and extracts from eucalyptus, neem, cinnamon,clove and tea tree. One may also use oil emulsions in preparing thefunctionalized particles in an aqueous medium and then remove the water,before adding these surface modified particles to the oil based paintformulations. Some of the other functionalizing agents for personal careproducts (see Table 1c which includes toothpaste, soaps, shampoos,creams, other hair care products, deodorants and nail polish) are thosewhich are used in such products, e.g., glycerin, benzyl alcohol, stearylalcohol, polyethylene glycol or polyperopylene glycol diester of stearicacid, sorbitol, cetyl alcohol, carrageenans, disteearyldiammoniumchloride, aloe leaf extract, cetearyl olivate, sorbitan olivate,caprylic/capric triglyceride, soyabean oil, olive oil, safflower oil,butylene glycol, potato extract, barley extract, sea-weed extract, wheatgerm oil, cocamidopropyl betaine, lactic acid, sodium hyaluroate, malicacid, algae extract, cholestrol, sucralose, witch hazel extract,hydrogenated lecithin, cycloymethicone, aqualine, linolicaciddimethicone copolyol, xanthan gum, polyethylene glycol (PEG) andpolypropylene glycol (PPG) dimethicones, sodium laureth-13 carboxylate,copolymer of methyl vinyl ether and maleic anhydride, bisamino PEG/PPG41/3 aminoethyl PG-propyl dimethicone, amine functionalized silicones(amidomethicone) and block copolymers of PEG and PPG (e.g., triblockcopolymer such as Pluronics™ available from BASF, Germany). PEG andpolyethyleneoxide are considered the same in this disclosure.

Other embodiments of functionalizing agents employ ligand-specificbinding agents. For example, functionalization using autoinducer orquorum sensing molecules (e.g., N-undecanoyl-L-Homoserine lactone andN-heptanoyl-L-Homoserine lactone) may facilitate the delivery of theantimicrobial materials through biofilms, and may help delay or preventthe formation of biofilms. Functionalizing agents may also have otheruseful or antimicrobial properties, which may be effectively combinedwith the antimicrobial particles. As examples, salts of argenine andacidic polymers have been suggested for use in toothpastes for promotingoral hygiene (US 2009/0202456), and chitosans and curcumin have beenalso suggested for use as antimicrobial materials and all of these maybe used as functionalizing agents.

Yet other examples include cecropin, caprylic acid and monocaprylin. Asanother specific example, it has been demonstrated (Corinne K. Cusumano,et al., Sci Transl Med 3, 109ra115 (2011) (DOI:10.1126/scitranslmed.3003021 “Treatment and Prevention of Urinary TractInfection with Orally Active FimH Inhibitors”) that mannoside compoundsare effective in preventing uropathogenic E. coli infections in women byinhibiting the ability of the bacteria to bind to epithelial cells ofthe bladder via FimH receptors. One may use such compounds to modify thesurfaces of particles of this invention to target E. coli withspecificity. In one embodiment, the mannoside compounds may be used asfunctionalizing agents for the metal salt nanoparticles of presentinvention. In another embodiment, mannoside compounds may be includedwithin the coatings used in urinary tract catheters.

The same approach may be used to target specific microbes responsiblefor specific pathogenic infections. There is an abundant and expandingliterature on receptors on cell surfaces to which microbes bind; andutilizing tailored compounds as functionalizing agents which interferewith such binding can readily be carried out. Beyond this, one ofordinary skill will be able to identify various ligand-targetcombinations to design any manner of ligand-specific targeting agents touse as functionalizing agents for the particles of the presentinvention.

Other embodiments of the invention include affinity-based targetingmechanisms such as using certain inherent properties of microbes'external structures to target the metal halide nanoparticles to. Forexample, the peptidoglycan layer of Gram-positive bacteria is a polymerof sugars and peptides and has a generally negative charge. Otherpolymers, such as PVP or PEG may be attracted to the peptidoglycansurface on the basis of hydrophobic interactions, and once there, maystick to and deliver the stabilized metal halide particles to thesurfaces of the microbes, which in turn will deliver theantimicrobial-active ionic species. Likewise, Mannose-binding lectin(MBL) and/or Lipopolysaccharide binding protein (LBP) may be included asfunctionalizing agents. MBL recognizes certain carbohydrate patterns onmicrobial surfaces and LBP binds to Lipopolysaccharide, which comprisesa majority of the outer membrane of Gram-negative bacteria.

In other embodiments of the present invention, after producing thefunctionalized particles in liquid media, these may be dried into solidpowders. Such solid powders are easier to store and transport and may bealso used in downstream processing with greater ease. The size of suchdried powders particles will in general be larger than the size of theindividual functionalized particles, and the particles of such driedpowder particles will contain a number of the functionalizedantimicrobial particles. The size of the dried powder particles shouldbe greater than about 1 microns, preferably greater than about 10microns and most preferably greater than about 100 microns. This allowsdownstream operations using the dry powders to be conducted safelywithout having the powder particles become airborne. The largerparticles do not get airborne easily and further 100 micron particlesize are larger than the thoracic airways of human lungs, Further, withincreasing size the particles are difficult to inhale and flowability inprocessing also improves.

The dried powders may then be used to make antimicrobial products byadding them to a liquid carrier or a solid carrier. Use of solidcarriers includes compounding these powders with a polymeric material inthe molten state. When these powder particles are added to the carriers(liquid or solid), these particles will generally break down and resultin a uniform dispersion of the smaller functionalized particles. Surfacefunctionalization may also assist in the size reduction of the powderswhen blended with the carriers.

In still other embodiments of the present invention, one may add otheragents (preferably other polymers) before the drying step used to formthe solid powders. This is useful for producing larger powder particlesupon drying. Such added agents can increase the cohesiveness of theassembly of functionalized particles and effectively serve as a binder,which is useful in providing stability during subsequent handling.Polymeric functionalizing agents may provide or contribute to thisfunction. Typically when the molecular weight of the functionalizingagent is less than about 500, it is advantageous to add a polymericbinder which preferably has a molecular weight greater than about 3,000.As an example, one may use PVP, PEO or other polymers along withsurfactants, where the surfactants have a molecular weight of less than500 and the polymers have a molecular weight of greater than 3,000.Preferably, the volume percent of the surface modifiers and thepolymeric additives should be in excess of 20%, and more preferably inexcess of 40%.

h. Porous Particles and Particles with Core-Shell Geometry

Other embodiments of the invention are directed to compositions havingantimicrobial activity comprising a metal halide, and a porous carrierparticle in which the metal halide is infused, the carrier particlestabilizing the metal halide such that an antimicrobially effectiveamount of ions are released into the environment of the microbe. Theterms “porous particle” and “porous carrier particle” are usedinterchangeably herein. In one embodiment, one may form theantimicrobial compositions within the porosity of larger porous carrierparticles. Metals and metal compounds or salts, particularly metalhalides are preferred materials for this infusion. For example one mayinfuse silver bromide or particularly copper iodide into the pores. Theporous particles should preferably have interconnected pores. Apreferred upper range of the carrier particle is below 100 μm, and morepreferably below 20 μm and most preferably below 5 μm. The average poresize (average pore diameter) of the carrier particles should be lessthan about 100 nm, preferably less than about 50 nm and most preferablyless than about 20 nm.

In other embodiments it is preferred that the surfaces of the porousparticles (including the pore surfaces) are hygroscopic (an abundance ofsilanol or other hydroxyl groups on the surface leads to hygroscopicmaterials). One preferred class of carrier particles that can be usedare “wide pore” silicas. The carrier particles may be of any shape,e.g., spherical, irregular, angular, cylindrical, etc. For example,SILIASPHERE™ silicas from Silicycle (Quebec, Canada) may be used. Thepreferred silicas have a pore size (average pore diameter) in the rangeof 2 to 100 nm, more preferably 4 to 20 nm). Another class of porousparticles includes precipitated silicas, such as Zeothix™ and Zeofree™from Huber Corporation (Atlanta, Ga.) and Sipernat™ from EvonikIndustries (Evonik Degussa Corporation, Parsippany, N.J.).

The porous carrier particles containing antimicrobial compositions inthe pores can then be incorporated into bulk products, coatings,solutions, low viscosity suspensions such as many shampoos, highviscosity suspensions such as creams and gels to impart antimicrobialproperties. These may be added as fillers to polymers which may then beshaped into bulk products via molding, extrusion, etc. Porous particlesmay also be prepared in a form of a large three dimensional shapes suchas plates, tubings or any other desired shapes. The AM material may beincorporated in these using solutions so that the bulk materials acquireantimicrobial properties. For example, a natural tubular material thatis mined may be used for this purpose. These are called Halloysite claysand are available from Applied Minerals (New York, N.Y.). These claytubes are typically between 0.5-3.0 microns in length, with an exteriordiameter in the range of 50-70 nanometers and an internal diameter(lumen) in the range of 15-30 nanometers. In addition to impartingantimicrobial properties, the use of these clays in plastics in lowconcentrations can also lead to enhancements in modulus, strength andabrasion resistance.

These porous materials are not used as ion-exchange materials as aretypical synthetic or natural zeolites, bentonite clays, hydroxyapatitesand zirconium phosphates. Such ion exchange materials contain molecularchannels with a size generally less than 1 nm which typically allow onlysingle ions and very small molecules to pass through. Further, ionexchange is conducted using solutions of salts with high watersolubility. For example, when conducting cationic ion exchange thecations from the salt are exchanged with the cations already present inthe ion exchange medium. For example, a zeolite or an ion-exchangeporous material may contain sodium ions in the framework of the porousmaterial. When this is exposed to e.g., a solution of silver nitrate inwater (silver nitrate is highly soluble in water and results in silverand nitrate ions), the sodium ions will be replaced or exchanged withsilver ions, so that gradually the aqueous medium will get moreconcentrated with sodium ions. After the process, the ion exchangedporous particles are washed to remove soluble salts and have a fractionof sodium ions replaced by silver ions.

In contrast to this, a salt or compound deposition process of thepresent invention is different and does not involve ion-exchange. Theantimicrobial salt is deposited in pores of selected porous particles.For example, if one wants to deposit a copper salt or a silver salt,then both the anions and the cations are deposited. Further, thedeposition process does not require that some other ion must beexchanged from the porous material. This deposition may be done fromsolutions which are soaked into the pores and dried, or soakingprecursors or precursor solutions in the pores so that they react anddesirable salts are formed within the pores, where they get trapped.Further, zeolites and the other ion exchange type materials are crystalswith well defined molecular channels. On the contrary, the preferredporous materials used in the present invention are amorphous and usuallyinexpensive, and their pores are typically larger and irregular. In ourinvention we deposit salts (both cations and anions) in the channels (orpores) of the porous materials and one can deposit more than one type ofantimicrobial salt or a compound. One can certainly mix the materials ofthis invention with other antimicrobials wherein the other antimicrbialsinclude silver, copper and/or zinc ion-exchanged zeolites. One may evenuse composite particles where the antimicrobial action comes from bothion-exchanged metals and deposited salts, wherein zeolites withsufficiently large pore size (preferably greater than 2 nm) are ionexchanged to contain at least one of silver, copper and zinc ions, andthen in a subsequent process low water solubility salt (e.g., salts ofcopper and/or silver) are deposited in these pores.

For deposition of metal compounds, particularly metal halides such ascopper iodide are dissolved in non-aqueous solvents such as acetonitrileand dimethylformamide (DMF). The porous particles are then treated withthese solutions so that they permeate the pores, and then excesssolution is removed. As the solvent from the pores is dried, theirremoval leaves the metal halide coatings/deposits on the particles andwithin the pores. This infusion of solution into the pores may beassisted by applying vacuum to the solution so as to extract air fromwithin the particles, and then the removal of vacuum allows the solutionto penetrate the pores more effectively. The porous carrier particlesare then removed (e.g., by centrifugation, filtering, etc.).

Solvent selection plays a fundamental role in the use of porous carrierparticles for delivery of inorganic metal compounds. Since an importantpart of the process is to ensure that solutions easily soak into thepores of the porous particles, it is required that the surfaces of thepores are compatible with the solvents used to form these solutions. Inone embodiment, when the surfaces of the pores have hydrophilicproperties, solvents with high dielectric constant such as water,ethanol, methanol, acetonitrile, dimethylformamide, etc., are easilywicked into the pores by capillary forces. The rate of release of ionscan be tailored by varying the size of the porous particles, particleshape and pore geometry (including pore size). In general, smallerparticle sizes, elongated or irregular particle shapes vs sphericalparticle shapes given the same particle volume, and larger pore sizeswill result in increased rates of ion release. One may mix differentsized particles and also particles with different pore sizes to tailorrelease properties to suit both short term and long term release of ionsin final products. Generally the size of the porous particles is variedbetween about 0.5 to 20 microns and pore size between 2 nm to 20 nm,with 4 to 15 nm being more preferred. These particles also have highsurface areas. Typically particles with surface areas greater than about20 m²/g are desirable, and those with surface areas greater than about100 m²/g are preferred.

The particles of this invention may also be fabricated in a core-shellgeometry, wherein the core may be a solid support and these are treatedwith solutions as described above so that these get coated with anantimicrobial material. That is rather then using porous particles,solid particles are used. Examples of core materials are silica,titania, sand and carbon. The amount of antimicrobial material in acore-shell particle is greater than 1% and preferably greater than 20%by weight of the total core shell particle.

Another variation in core shell geometry is where the antimicrobialparticles are first formed in a desired size and then these areencapsulated in porous or permeable shells so as to allow theantimicrobial material or the ions to pass through.

In another process embodiment, non-water soluble (or with low watersolubility) metal halides may be formed in the pores using aqueoussolutions. Aqueous solutions are formed using water soluble salts of thedesired metals (precursor salts). The porous carrier particles aretreated with these solutions and removed. These particles may beoptionally dried. The treated particles are then treated with a secondsolution comprising another water soluble salt with the desired halideanion. When the second salt solution permeates the pores of theparticles and comes in contact with the with the precursor salts, therequired metal halides (with low water solubility) form by precipitationas the two salts react and are trapped in the pores of the particlesresulting in antimicrobial particles. If surface functionalization ofthe deposited materials is desired, one of the said halide saltsolutions may include surface functionalization agents. After drying,these particles may then be subjected to another series of similartreatment to precipitate more of the target metal or metal compound, orto precipitate a second compound or metal in the pores (e.g., depositingAgBr in pores which previously have been treated to deposit CuI). Onemay also form antimicrobial particles by mixing different types ofporous particles comprising different compositions of metals and metalcompounds. One particular embodiment comprises forming antimicrobialcompositions by mixing two or more types of particles with differentantimicrobial materials trapped in their pores. These formulations maythen be added to products in order to form products with antimicrobialproperties.

In a process embodiment of the present invention, one may also formantimicrobial porous particles with deposits of silver metal. Suchparticles can then be used to make antimicrobial formulations. Theinfusion of silver metal in a porous carrier particle is generallyperformed by starting with an aqueous solution of a metal salt (e.g.silver nitrate with the surface modifiers (if used) dissolved therein)in water. The porous particles are added to this solution so as toinfuse the solution into the pores. This infusion may be assisted byapplying vacuum to the solution so as to extract air from within theparticles, and then the removal of vacuum allows the solution topenetrate the pores more effectively. The porous carrier particles arethen removed (e.g., by centrifugation, filtering, etc.) and optionallydried. The particles (wet or dry) are then added to an aqueous solutionof reducing agent (e.g., 0.25% w/w NaBH₄) which causes small particlesof the metal (in this case, silver) to precipitate within the pores andalso on the surfaces of the porous carrier particles.

i. Formation of Functionalized Particles by Grinding

In an earlier section on functionalization materials, several exampleswere cited which used grinding as a method to produce functionalizedparticles. Generally the starting particles of the antimicrobialmaterials have an average size larger than 1 micron, typically in therange of 1 to 1,000 microns. These are reduced in the grinding step toan average size below 1 micron (1,000 nm) or even below 100 nm or evenbelow 10 nm depending on the desired size. This process is described inmore detail in this section.

In this operation the functionalization materials are incorporated intothe grinding medium or incorporated soon after the grinding operation.There are many advantages of the grinding process which include: (a)increased yield both in terms of amount and the concentration of theparticles produced. (b) scalability on an industrial scale; (c) reducedwaste both in terms of hazardous chemicals and also in terms ofadditional equivalents of starting materials that are typically requiredin chemical synthesis methods; (d) reduced energy requirements in termsof simplified processes and handling, removal and drying of largerquantity of solvents relative to the material produced; (e) reduced costof production while adopting “clean and green” manufacturing methods;(f) increased versatility in terms of the chemistry of thefunctionalizing agent; (g enhanced capability in being able to use morethan one functionalization agent with different chemistries; (h)avoidance of the long development process which is typically requiredfor each new set of particle composition and functionalization agentwhen chemical synthesis methods are used; (i) new capability ofimparting additional attributes to the antimicrobial materials via thefunctionalization agents; (j) increased ability to tune/control the sizeof the resulting particles from a few nanometers to 1,000 nm or above;and improved ability to produce fine antimicrobial particles withoutintroducing undesirable amounts of functionalization agents.

As an example, in many of the chemical synthesis methods wherefunctionalized particles are made in solvent systems, such as making CuIparticles functionalized with PVP, the latitude for processing and thematerials used is quite limited in terms of the type of the chemistry ofthe antimicrobial particle being formed and also the chemistry of thesurface functionalization material. First, both the antimicrobialmaterial (e.g., CuI) and functionalization agent (e.g., PVP) have to besoluble in a common solvent (such as acetonitrile). Second, the amountof functionalization agent required is very high when small particlesare produced—typically the weight ratio of antimicrobial particlematerial to the surface functionalization agent is about 5:100 or less,and generally 1:100 or less. This results in significant amount of thefunctionalization agent which ends up in final products and oftencompromises the properties of those products. In the grinding method onemay use a very high weight ratio of antimicrobial particle material tothe surface functionalization agent, such as 1:1 or higher, andpreferably equal to or greater than 3:1 and more preferably equal to orgreater than 9:1. Third, one must handle and dispose of the solvent usedin the synthesis, which introduces additional cost and complexity to theprocess. Fourth, it can be a major undertaking to change the chemistryof the particles or the functionalization agent.

As another example, consider the limitation of the chemical method whichis typically used for making silver iodide nanoparticles. Theseparticles are made by taking an aqueous solution of a soluble silversalt such as silver nitrate along with a water-soluble polymer such asPVP. To this under stirring conditions is added another aqueous solutionof sodium iodide (sodium iodide is soluble in water as well). Thiscauses silver iodide particles to precipitate. In this case, the ratioof Ag to the functionalization agent is also about 1:100, with an addedcomplication of removing sodium and nitrate ions. Further, if one needsto add 0.1% of the antimicrobial agent to a product, then thefunctionalization agent would be present in a 10% concentration. Suchlarge additions of the functionalization agents may considerably modifythe properties of the product in an undesirable way, unless suchfunctionalization agents are present in the product in significantconcentrations to impart other attributes (e.g., plasticizers, carriers,gelling agents, monomers that react to form the polymer—such as inpolyurethanes, epoxies, etc.). Still further, difficulties areencountered if one wants to functionalize with materials which are notsoluble in water; and new synthesis routes must be explored if one wantsto change the chemistry of the antimicrobial particles.

One may also produce functionalized particles by grinding in presence ofmonomers which include metal oxide precursors. This grinding may be doneat a first pH, and after grinding, the pH is changed to a different or asecond pH to promote additional reactions. As an example, one may grindthe desired metal halide in the presence of a silica alkoxide precursorsuch as tetraethylorthosilicate (TEOS) in an acidic medium (e.g., pHlower than 7) so that the monomer is able to hydrolyze and attach to thesurface of the ground particles. Once the grinding is over the materialin a subsequent step is removed and the pH is changed (e.g., it israised to over 7) so that the silica precursor functionalizing theparticles condenses and forms a porous medium around the groundparticles. An additional grinding process may be introduced after theprevious step to break any particle agglomerates. One may also mix morethan one precursor during grinding (e.g. mixtures of metal alkoxides orother precursors of the same metal or of different metals). One may addall of the precursor before grinding or add them sequentially during thegrinding process and the addition may even continue even after thegrinding is completed. The composition and/or quantity of each additionmay be the same or different. The particles obtained after the grindingoperation may be refluxed to promote condensation of thefunctionalization agent while still in a liquid matrix, or dried andthen subjected to higher temperature heat treatments for reducing theporosity. Further, one may even heat treat the particles to asufficiently high temperature to burn off any residual organics whichmay be present in the formulation. As a variation one may producefunctionalized particles with any desirable material (e.g., PVP) bygrinding, and then add a monomer and polymerize this to furtherencapsulate the functionalized particle.

As an additional example, many useful paints and varnishes are depositedfrom aqueous formulations containing polymeric emulsions. Typicallythese polymers are not water soluble so that the coatings after dryingare water-resistant; but for processing, these polymers are madecompatible with water formulations by polymerizing them in water withsurfactants so that water-stable emulsions can be formed. Since a widerange of polymers are used with many different kinds of surfactants, itis very challenging to develop chemical methods to accommodate thedifferent emulsions and particles. In contrast, in the preferred processembodiment of the present invention, CuI (or another antimicrobialmaterial) can be ground with these emulsions (or surfactants used toform these emulsions) to make antimicrobial formulations in a simpleway. The process does not require addition of any extra ingredientswhich have the potential to change the properties of products containingthe antimicrobial particles. Further, formulations made using thepresent process invention can be used as such and do not requirehandling of solvents and their removal, or production of byproductswhich need to be removed, all of which lead to greener productiontechnologies with lower energy consumption.

There are many examples and teachings in the present application whichdemonstrate one or more merits of the grinding method.

One such method of forming the desired microparticles and nanoparticlesis by grinding of larger particles in a wet media mill. Such grinding isdone in the presence of one or more functionalizing agents in anappropriate liquid medium, e.g. water. Wet media mills are availablefrom several sources such as NETZSCH Fine Particle Technology, LLC.,Exton Pa. (e.g., Nanomill Zeta®); Custom Milling and Consulting,Fleetwood, Pa. (e.g., Super Mill Plus); Glen Mills Inc, Clifton N.J.(e.g., Dyno® Mill). These mills typically comprise chambers in whichhard ceramic or metal beads (grinding media) are vigorously stirredalong with the slurries of the powders which result in grinding of thepowders down to finer sizes. Typically, the size of the beads is about1,000 times or more larger than the smallest average size to which theparticles are ground to. In a single step grinding process, it ispreferred to use beads about 1 mm or smaller and more preferably in therange of about 0.04 to 0.5 mm and most preferably 0.3 mm or smaller. Thegrinding procedure may start with a larger bead size to grind initiallythe large chunks/particles of antimicrobial material to a smallerparticle size and then using smaller beads to reduce the particle sizefurther. As an example, when one starts grinding particles which have astarting size in the range of about 30-50 microns, a bead size of 0.3 mmmay be used, which will result in particles of about 100-400 nm inaverage size. In the next stage, one may use beads of 0.1 mm in diameterwhich results in particles ground to about 30-100 nm, and next one woulduse 0.05 mm diameter beads which provide particles in the range of about15-50 nm. The particle size of the ground particles is not onlydependent on the size of the beads, and other grinding parameters suchas time and speed of grinding, but also on the formulation. As anexample, for a given set of grinding parameters, the concentration ofmaterial being ground and the type and amount of surfacefunctionalization, the amount of viscosity controller (if any) and otheradditives will influence the particle size. For a material being groundin water (carrier), the following formulation variables will reduce theparticle size when the same grinding parameters are used. These are (a)smaller amounts of material relative to the carrier, (b) use of afunctionalizing agent that bind strongly to the surfaces of theparticles of the material being ground, and (c) use of functionalizingagents that result in low viscosity. Under certain conditions one canproduce particles as small as 5 nm using grinding beads which are 0.1 mmin size. Functionalizing agents may be present at the start of thegrinding process (preferred), or more amounts or different agents may beadded as the grinding proceeds.

A wide range of particle sizes may be used to provide antimicrobialproperties to products incorporating such particles, but particle sizesbelow about 300 nm are preferred. The liquid media from the grindingcontaining the ground particles may be directly incorporated in products(e.g., in coating formulations, low viscosity suspensions such as manyshampoos, high viscosity suspensions such as creams and gels, etc.), orthese may be dried (e.g, using a rotary evaporator unit or by spraydrying) so that the particles along with the functionalizing agents areobtained as powders or flakes, where these powders or flakes particlesare preferably sufficiently large to minimize potential health issuesfor workers handling the materials. The particles or flakes may then beincorporated in useful formulations including melt blending with otherpolymers to form products by molding, extrusion, powder coating, etc.

In order to obtain dry powders, where the size of the powder or flakematerial is large (preferably greater than 1 microns, more preferablygreater than 10 microns and most preferably greater than 100 microns),where powder or flake particle contains several functionalized antimicrobial particles, it is preferred that before drying the liquid,sufficient functionalizing agents and/or polymers (e.g., which canprovide a binding function) are added, so that the volume percent of thefunctionalizing agent and the polymeric material is preferably greaterthan 20% or more preferably greater than 40% in the dry state. Thebinding additives (if different from the functionalizing agents) mayalso be added after the grinding process is complete, As a specificexample, one may use 60-95% of metal halide (e.g., CuI) particles byweight, with 1-5% of an anionic surfactant and/or other ingredients byweight, and the remainder being a polymeric binder by weight. This wouldmeet the volume percentage criteria taught immediately above. As anexample a formulation with 90% CuI and 10% PVP (both by weight assolids), when converted to volume fraction using their respectivespecific gravities of 5.67 and 1.2 would result in about 66% of CuI byvolume and 34% PVP by volume.

It is preferred to add the functionalizing agents while the particlesare being ground and smaller particles with fresh surfaces are produced.There is, however, an exception to this process protocol which can beuse to advantage. The particles may be produced by grinding so as toreduce the size of the larger particles of the antimicrobial material inwater (or acidified water) or even in an inert liquid medium. After thegrinding process is substantially over, i.e., after the desired particlesize is about reached, the surface functionalization agents are addedand a short period of additional grinding is carried out to produce thedesired functionalized particles. One may also add more than onefunctionalization agent, where these may be added together or atdifferent times.

When grinding is carried out in an aqueous medium, where surfacehydroxyl groups on the particles (formed as a result of grinding inwater), the functionalizing materials should be so selected so that theycan interact with these hydroxyl groups and bond to or react with them.If the grinding is carried out in an inert medium, the functionalizingmaterials should be selected so as to be able to interact with the newlyformed surfaces.

In those processes where the functionalizing agent is added after thegrinding operation, these agents are preferably added before theparticles start agglomerating into larger sizes. From our practicalexperience we have noted that this addition of the functionalizationagent should preferably be done within 48 hours of grinding, and morepreferably immediately after grinding. One may even optionally introducea second step of grinding after adding the surface functionalizationagent for more intimate and a quick dispersion of the added material andalso to break agglomerates that may have formed during the waitingperiod. More than one functionalization agents may be added during thegrinding process. These may be added together or at separate ordifferent times. For example the grinding may commence with onefunctionalization agent and later more of the same or a differentfunctionalization agent may be added.

One advantage of using the grinding process to produce functionalzedparticles of antimicrobial materials is the ability to use mineralswhich have antimicrobial compounds naturally incorporated in them. Suchminerals can be ground to provide antimicrobial materials. Such grindingis preferably done in presence of functionalizing agents. Some examplesof minerals with silver or copper halides along with their principalcompositions are Iodagyrite (AgI), Bromargyrite (AgBr), Chlorargyrite(AgCl), Iodian Bromian Chlorargyrite (Ag(I, Br, Cl)), Nantokite (CuCl)and Marshite (CuI).

Another significant advantage of grinding is to be able to use severalmaterials for functionalization which may be used simultaneously. Morespecifically, one can use complete formulation of a product tofunctionalize the particles. For example, these may be complete orpartial personal care formulations, drug formulations, etc. Somespecific examples are shampoos, soaps, mouthwash, deodorants,toothpaste, etc. For example in a toothpaste, the formulation used ingrinding may be partial i.e., before adding opacifiers or dentrifices,etc. If the formulations are solids then these can be dissolved ordiluted using solvents (e.g., dissolving solid soap in water), etc.Solvents may be removed before adding them to the final product or thesemay be removed after adding them to the final product. This is similarto making a concentrated masterbatch of the functionalized particlesusing final formulation (or a partial formulation), and then mixingthese in the final product in the desired antimicrobial concentration.

The grinding method is generally more suitable for materials which arebrittle and have a hardness and toughness lower than that of thegrinding beads. The principal material to be ground should be lower inhardness as compared to the grinding beads. On Mohs scale, the hardnessof the principal material to be ground should preferably be smaller thanthat of the grinding media by a factor of at least 2 Moh units or moreand more preferably 3 units or more. Further the principal material tobe ground should be brittle. In general, brittle materials often havefracture toughness (K_(1C)) of less than 2 Mpa-m^(1/2). Many of themetal halides and the preferred metal salts of silver and copper areavailable as powders, and their fracture toughness is not mentioned orevaluated. However, most of these materials (silver halides, copperhalides, CuSCN and Cu₂O) are soft and brittle (not malleable) by natureand are easily processed by grinding. Usually copper and silver halideshave hardness in the range of 2 to 3 on the Moh's scale, and Cu₂Ocrystals have a hardness in the range of 3.5 to 4 on the same scale. Theprocess of grinding to make functionalized antimicrobial nanoparticlesdiscovered in the present work is applicable to a wide range of metalhalides and other copper salts of interest. The process is also usefulfor preparing functionalized particles of other compounds (e.g., AgBr,AgI), such as brittle metal oxides (e.g., zinc oxide, silver oxide andcuprous oxide).

The lining of the grinding vessel may be ceramic or of metallic or mayhave a polymeric finish. Typical grinding beads are hard, tough ceramiccompositions such as compositions based on zirconium oxides (zirconia).Hard beads with zirconia comprising at least one of yttrium oxide,magnesium oxide, cerium oxide and calcium oxide are commerciallyavailable. The. Some suppliers for stabilized zirconia and or aluminabeads (grinding media) include yttria stabilized zirconia (YTZ) beadsfrom Tosoh USA (Grove City, Ohio) which have 5% yttria and 95% zirconiawith a hardness of HV 1250 and fracture toughness of 6 MPa-m^(0.5),others are Prime Export and Import Company Ltd (China), StanfordMaterials (Irvine, Calif.), Inframet Advanced Materials (Manchester,Conn.) and ZGC beads from 3M (St. Paul, Minn.). Typically, the materialis ground in a liquid medium which does not solubilize the materialbeing ground. However, it may be beneficial to add a limited amount ofsolvent (which by itself will solubilize the material being ground) tothe grinding medium to increase the process efficiency of grinding.These are added in addition to the surface functionalizing agents. It ispreferred that this solvent is compatible with the liquid medium. As anexample in grinding copper iodide, one may use water as the grindingmedia and acetonitrile as the solvent additive. Typically solventconcentration to the liquid medium is less than 20% by volume, andpreferably less than 10%. One may also use azeotropic mixtures of thesolvent and the liquid medium as long as the solubility of the materialis low, preferably less than 100 ppm.

One may grind more than one material to produce functionalized particlesof several chemistries simultaneously. For example, one may grind morethan one copper salt, or mixtures of copper and silver salts, etc. Someof the preferred combinations include copper halides and silver halides,e.g., CuI and AgBr; or CuI, AgBr and AgI; or CuI and AgI, etc.

We have also found that when the functionalized particles are formed bygrinding, small amounts of materials in their elemental form may beadded during the process. These include metals. These metals interactwith the surface of the particles and the functionalization agents tohelp control the coloration of the formed materials and also inmodification of antimicrobial properties. Some of the preferred metalsare gold, silver, copper and zinc. An example of a nonmetal is iodine.

j. Highly Water Soluble Salts

We have also seen that selective water soluble salts help withdispersion, i.e., stabilization of particles in a liquid medium orbetter dispersability in a solid medium. Typical solubilities of thesewater soluble salts are preferably in excess of 1 g/liter. These salts(organic or inorganic) typically have strong interactions with thematerial being ground and are preferably used in association withsurface functionalization agents. The addition of water soluble saltswith antimicrobial properties may also help in providing antimicrobialefficacy at different time points (e.g., a burst of activity at shortertimes). They may also provide buffering effects, or control the redoxproperties of the ions (e.g., stabilizing cuprous ions, or stabilizingiodide ions in compositions comprising cuprous and/or iodide ions), orprovide compatibility with other ingredients in the composition. Theantimicrobial compositions may be used as suspensions in aqueous ornon-aqueous liquid media, or be solids.

Some example of soluble salts which have shown promise with metalhalides of low water solubility (particularly copper and silver halides)include organic salts and salts of elements selected from at least oneof lithium, sodium, potassium, calcium, magnesium, barium and zinc.Further, the antimicrobial compositions may also comprise high watersolubility salts of copper, silver and nickel. Some specific examples ofhighly water soluble salts are sodium acetate, sodium citrate, sodiumcinnamate, sodium gluconate, similar salts of potassium, calcium, copperand silver; halide salts of lithium, sodium and potassium, calcium,magnesium zinc and copper; silver nitrate, sodium and potassiumthiosulfate.

2. Theory

While not wanting to be bound by a particular theory regarding theorigin of the surprising antimicrobial effectiveness of the novelcompositions of the present invention, it is currently believed that thecompositions of the invention (or ions released therefrom) are attractedto the surfaces of target pathogens. Once attached to the surfaces ofthe pathogens, the active oligodynamic species (generally metal cationsbut also including anions such as iodide) are transferred from theparticles onto and/or into the pathogens. In some embodiments, theinteraction between the functionalized particles and the pathogens maybe sufficiently strong that the particles become embedded in the outermembrane of the pathogen, which can have a deleterious effect onmembrane function. In other embodiments, particularly when the particlesare very small (as less than 10 nm in size), the functionalizedparticles can be transported across the outer membrane of the pathogenand become internalized. Under these conditions, the oligodynamicspecies can directly transfer from the particles into the pathogen, bindto proteins, organelles, RNA, DNA etc. thereby hindering normal cellularprocesses. In the case of bacteria, this would correspond to the directdeposition of the active oligodynamic species in the periplasm orcytoplasm of the bacteria. This theory of the operative mechanism of theinvention is just that, and is one of many that could explain theunderlying efficacy.

3. Uses of the Compositions and Incorporation Methods in Products

The embodiments of the present invention have utility in a wide range ofantimicrobial applications. These applications or products may beliquids or solids. Some of these applications are set forth in Table 3below. Besides their direct use as antimicrobial compounds, otherembodiments include several ways in which the functionalized particlescan be incorporated into other materials to obtain novel and usefulobjects.

TABLE 3 Representative applications of functionalized antimicrobialparticles No. Application 1. Antimicrobial agents, administered eitherorally or via IV infusion 2. Coatings on medical implants 3.Constituents of medical implants 4. Sutures and medical devices 5.Pacemaker and hearing aid housings and leads 6. Coatings on orconstituents of ventilator equipment, particularly the humidificationcomponents of such equipment 7. Medical and surgical gloves 8. Masks 9.Dental adhesives, primers, sealants and composite fillings used fortooth restoration, and other tooth restoration products such asdentures, crowns, bridges and coatings including coatings on implants.10. Objects and coatings to prevent formation of biofilms, in medicalapplications, e.g., urinary tract and long dwell catheters 11. Topicalcreams for medical use including use on wounds, cuts, burns, skin andnail infections 12. Use in wound dressings (includes gauzes, bandages,etc.) 13. Coatings on bottles, containers or incorporated into thematerial of the containers used for containing medical or ophthalmicsolutions 14. Clothing for medical personnel, including nurses andsurgeons 15. Textiles including bedding towels, undergarments, socks,sports- wear, uniforms and technical textiles (antimicrobial agent is infibers or as coating on fibers or fabrics) for microbial and odorcontrol 16. Coatings on and constituents of shopping bags 17.Upholstery, carpets and other textiles, wherein the particles areincorporated into the fibers or as coatings 18. Self disinfecting wipes19. Coatings on or direct incorporation in components of ventila- tors,air ducts, cooling coils and radiators (for use in buildings andtransportation) 20. Coatings on furniture for public use, such as inhospitals, doctors' offices and restaurants 21. Wall coatings inbuildings, and incorporation as coatings or in bulk of buildingcomponents such as floors, appliances, bathroom surfaces, handles,knobs, sinks, toilet seats, shower heads, tables and seatingparticularly public buildings such as hospitals, doctors' offices,schools, restaurants and hotels 22. Coatings or compositions tor use intransportation, such as ships, planes, buses, trains and taxis, wherethe antimicrobial compositions and coatings may be used for/applied towalls, floors, appliances, bathroom surfaces, handles, trays, steeringwheels, knobs, tables and seating 23. Coatings on school desks 24.Coatings on plastic containers and trays 25. Coatings on leather,purses, wallets and shoes, and also incorporating antimicrobialmaterials with the bulk of the materials to make these (e.g. shoe soles,and uppers), odor control 26. Coating of flowers and flower heads 27.Incorporation in gloves, and liners for gloves, shoes and jackets 28.Filters for water supplies and air, water and air delivery systems, airhumidifiers 29. Use as a biocide in aqueous systems 30. Coatings forprevention of biofilms on marine applications 31. Coatings on or directincorporation in keyboards, switches, knobs, handles, steering wheels,remote controls, of automobiles, cell phones, optical video and datadisks and other portable electronics 32. Anodized coatings 33. Powderand coil coatings including for applications in furniture, appliances,handles, knobs, etc. 34. Coatings on toys, books and other articles forchildren 35. Coatings or or incorporation in gambling chips, gamingmachines, dice, etc. 36. Bottle coatings for infant's bottles 37.Coatings on cribs and bassinettes 38. Coatings on handles of shoppingcarts 39. Coatings or direct incorporation in personal items/use such astoothbrushes, hair curlers/straighteners, combs and hair brushes,brushes for cosmetic application (both for application of dry and wetmaterials) 40. Liquid cleaners/treatments/disinfectants (includingsprays) for surfaces in household, industrial and medical facilityapplications 41. Nail polish including base and top coats 42. Shampoosfor treating chronic scalp infections, antidandruff shampoos, hairdetangling treatments, hair gel and other hair treatments 43.Incorporation in tooth paste, mouthwash and tooth brushes 44. Anti-odorformulations, including applications for personal hygiene such asdeodorants 45. Other body care products such as creams (includingmoisturizing and anti wrinkle creams, UV protection creams), shavingcreams/ gels, soaps (liquids, gel and solid), sanitizers, powders,mascara, blush, foundation and other cosmetic applications. 46. Coatingson currency, including paper, tissue paper, plastic and metal 47.Coatings or direct incorporation in sporting goods such as handles forrackets and bats used in various sports, golf clubs, golf balls, fishingrods and exercise machines. Other sporting goods such as balls forvarious sports including bowling balls 48. Foams (flexible and rigid)49. Molded and extruded products, including waste containers, devices,tubing, films, bags, packaging (including food packaging), linersgaskets and foam products. 50. Adhesives (includes caulking materials),gaskets thermosetting materials and composites 51. Disinfectants foragricultural and food use to kill microbes and prevent their growth oncrops, algae control, control of mollusks, insecticide, treatments formeat, vegetables, and fruit. 52. Biocides to treat water bodies, liquidwastes, industrial, processes, hydraulic fracturing fluids, treatment ofoil and gas wells, and their use in other aspects of petroleum industry53. Products for pets- toys, treats, food 54. Printing inks, both forconventional and 3-D printing

The compositions of this invention may be incorporated in liquid orsolid carriers to yield products with antimicrobial properties. Manysuch examples and methods of incorporation will be discussed below.

Incorporation of the functionalized particles of the invention in moldedand extruded thermoplastic products is typically achieved by firstmaking masterbatches, wherein the functionalized antimicrobial compound(or particles infused in porous matrices) are present in relatively highconcentrations in polymeric matrices (preferably 1 to 15% of metal byweight (present as metal compound)). The masterbatches are thencompounded with the polymer (resin) to make the molded or extrudedproduct. This is typically done by first functionalizing theantimicrobial particles with agents which are compatible with the matrixresins. The functionalized particles are formed in a dry state byremoving water or any other solvents which are used in their preparationand mixing them with the desired resins, usually on a mill or a twinscrew extruder so that these mix intimately to have a high concentrationof the antimicrobial compound. As noted above, this is called a“masterbatch.” This masterbatch is typically produced by companies whichspecialize in homogenously blending the two together and deliver theirproducts as pulverized powders or pellets.

The masterbatches are then used as additives to the matrix resins byprocessors who use molding and/or extrusion operations to make products.Such plastic processing operations include injection molding, injectionblow molding, reaction injection molding, blown film processing, blowmolding, rotational molding, calendaring, melt casting, thermoforming,rotational molding and multishot molding. Starting with theantimicrobial concentration in a masterbatch as cited above, theprocessors use a typical ratio of resin to masterbatch material of 10:1to about 25:1 or so, which will then result in end products withconcentrations of antimicrobial materials of about 0.02 to 1% (based onmetallic concentration). Typically for metal halides, these weightfractions are expressed in terms of the weight of the cations only.

To protect the health and safety of the workers employed in such afacility or other downstream processor, it is important to minimize thepossibility of getting the nanoparticles airborne. An effective methodof accomplishing this involves making the particle size of the driedpowders containing the antimicrobial particles relatively large comparedwith the size of the individual nanoparticles. The size of the driedpowders should be greater than 1 micron, preferably greater than 10microns, and most preferably greater than 100 microns. Such dry powdersare easily handled and transported for downstream operators to use inpaints, resins and other liquid carriers to create coatings or objectsincorporating the functionalized nanoparticles.

The masterbatch can be blended with the neat resin using processingequipment such as injection molding or extrusion machines, which makesthe final product. The final products can be a variety of moldedproducts extruded products (including tubes, bottles, fibers for use infabrics/textiles and carpets). In some materials presence of copperiodide particles may lead to issues related to color fastness. For theseone may add additional stabilizers. For example, halide salts (e.g.,potassium iodide, see U.S. Pat. No. 4,745,006 and Janssen K. et al,Polymer Degradation and Stability, Vol49, p 127-133 (1995)) may be addedin 5 to 10 times in excess of the iodine provided by copper iodide.

Antimicrobial compositions of this invention may be added to extruded ormolded polymer products homogeneously or may be applied to these objectsas coating layers using operations such as extrusion or molding. In thelatter case, operations such as co-extrusion, in-mold decoration,in-mold coating, multi-shot molding, etc are used where theantimicrobial additive is only present in that resin/material whichforms the skin of the product as a result of these operations.

The functionalized microparticles and nanoparticles of the presentinvention may also be used by combining them with monomeric compositionsor with solutions of pre-formed polymers, where the resulting materialscontaining the functionalized particles may be used to create two- andthree-dimensional objects, adhesives and coatings, where thecompositions are polymerized or crosslinked or densified afterprocessing/setting the compositions into their final form. Coatings mayalso be deposited from solutions and aqueous polymeric emulsionscontaining the functionalized antimicrobial particles, where theformulations preferably comprise one or more film-forming polymers, orthe particles may be employed in powder-coat formulations which are thenprocessed into coatings.

Antimicrobial inks comprising functionalized particles of this inventionmay be formed using techniques known in the art of printing inks Suchinks may be printed using a variety of techniques such as inkjet, flexo,gravure and silk-screening. In some cases, such as in inkjet printing,the size of the functionalized particles should be smaller than about 50nm. Three dimensional antimicrobial products may be formed by 3-Dprinting, where the inks incorporate the antimicrobial materials of thisinvention.

Water based acrylic, epoxy and urethane paints are used in manyapplications. These are typically emulsions of hydrophobic polymers inwater. After application to a surface, the water evaporates and theemulsions coalesce leaving a hydrophobic coating. In order to impartantimicrobial properties to these coatings, one can take these emulsions(preferably before fillers are added) and grind the antimicrobialparticles in their presence to produce antimicrobial particlesfunctionalized by these emulsions. The antimicrobial material can be inhigh concentration and such concentrates may be added to the paintformulations to provide antimicrobial properties to the coated objects.Alternatively, one may also grind the antimicrobial material with acompatible functionalizing agent (such as a surfactant) which may evenbe the same as the surfactant used as an emulsifier in the paint, andthen such powder can be added to the paints. In yet another method,porous carrier particles with antimicrobial particles therein can beproduced, which are then added to the paint formulations.

As another specific example, these methods may be used to incorporateparticles of this innovation in formulations of nail polish (a coatingapplication), which are available as water or solvent based. Typicalsolvents used in nail polish are acetates (e.g., butyl acetate). Theparticles may be ground with using solutions of the polymers and/orsurfactants which are used in these applications and are then added tothe final nail polish composition. Since the final compositions arequite viscous, it is often desirable to grind the particles separatelyas suggested above, or the complete nail polish formulation with excesssolvent may be used as the liquid medium, and the excess solvent isremoved later. While these nail polishes can provide protection bypreventing microbial growth, such nail treatments may also be used toactively treat nail fungal infections. Nail polish products includeformulations which are used for base coat or a top coat in the nailpolish industry. Antimicrobial additives in base coat are particularlydesirable to protect fungal or other microbes from one person to betransferred to another person particularly in nail salons. Antimicrobialadditives to top coats will prevent any microbe harboring on the surfacewhich may grow and get transferred to others during contact, etc. Nailpolish products which may have higher water permeability (orbreathability in excess of about 0.4 mg of water/cm²-hr), may be moreprone to bacterial infections, and addition of antimicrobial agents andparticularly those of this invention would be highly beneficial inkeeping the nails microbe resistant. There are many products in themarket offering nail polishes with high water permeability. Someexamples are O2M line of enamels from Inglot Sp. Zo.o. (Poland),Acquarella nail polishes from Acquarella LLC (Tucson, Ariz.).

When used in coatings and molded and other three dimensional products,the particles may scatter light, depending on their concentration, sizeand refractive index relative to the matrix. This can give rise toopacity or haze with increasing product thickness, larger particles,higher particulate concentrations and larger differences between therefractive index (RI) of the particles and the matrix. In manyapplications, this is not an issue, since the products contain otheropacifiers such as titanium dioxide. In other cases, e.g., for opticaland ophthalmic products, or products where coatings should not interferewith the appearance of the substrates, optical clarity is important. Onemay use the materials of the present invention provided the above-citedparameters are controlled. The RI of most common polymers is in therange of 1.4 to 1.6. Silicones will be closer to 1.4, acrylics closer to1.5 and polycarbonate closer to 1.6. By comparison, the RI of copperiodide (as an example) is 2.35. For high clarity (or low haze, typicallyless than 2% haze (preferably less than 1% haze and more preferably lessthan 0.5% haze) in the visible wavelengths as measured by ASTM testmethod D1003), it is preferred that the average size of CuI particles beless than about 200 nm (preferably less than about 120 nm), volumeloading less than about 2% (preferably less than about 1%) and productthickness less than about 0.25 mm (preferably less than about 0.1 mm).AgI, AgBr, CuBr, CuCl and Cu₂O have lower refractive indices comparedwith that of CuI and will allow relaxation of these numbers (meaninglarger particle sizes, higher volume loading and thicker products inproducts of high clarity). However, some of these materials with lowerrefractive index may impart stronger colors which may be undesirable.

Functionalized antimicrobial particles may be produced in aqueous media(e.g., by grinding or the other described processes) and added to theleather tanning solutions. When leather is soaked in these solutions andlater dried, it will retain the antimicrobial particles which willresult in antimicrobial leather. In carrying out this process, theleather may be soaked in the antimicrobial solutions after fats and oilshave been removed and washed or may be incorporated within the tanningsolution.

As yet another example, one may also produce antimicrobial foams whichare used for a number of applications. For example, polyurethane foamsare made using a formulation produced by mixing an isocyanate with apolyol (a molecule with three or more hydroxyl groups) a chain extender(a bifunctional hydroxyl molecule), catalysts to promote reaction,surfactant, heat and/or UV stabilizers along with a foaming agent. Thefoaming agent could be water as it produces carbon dioxide gas when itreacts with the isocyanate. One method of making antimicrobial foamsinvolves producing antimicrobial particles with a surfactant (using asurfactant compatible with the system or the same which is used in thesystem) or one of the urethane-forming constituents and adding these tothe foam formulation. Another alternative involves producingnanoparticles in an aqueous media, such as by grinding them in wateralong with the desired surfactant and then adding this aqueous mixtureto the foam formulation both as a foaming agent and as an antimicrobialsource.

Another method by which they may be added to solid carriers is bygrinding the antimicrobial materials in liquid plasticizers. As anexample, phthalate ester plasticizers may be used as a liquid medium forgrinding the antimicrobial material in the presence of a functionalizingagent; and when such ground compositions are added to plasticizepolyvinylchloride (PVC), than the resulting plasticized PVC acquiresantimicrobial properties. Alternatively, one may also grind theantimicrobial material with a compatible surface functionalizing agent(such as a surfactant) which is then added to the plasticizer beforeincorporating this mixture into the polymer.

Imparting a thin coating to a surface allows one to obtain antimicrobialproperties on a surface without infusing the potentially expensivematerials into the bulk of the object. As an example, powder coatingswith the antimicrobial additives of this invention can be formed onmetals, and even on non conductive surfaces such as wood, ceramics andother polymers (thermoplastics and thermosets). The technology forpowder coating of materials is well established (e.g., see “A Guide toHigh Performance Powder Coating” by Bob Utec, Society of ManufacturingEngineers, Dearborn, Mich. (2002).) The matrices for powder coats aretypically epoxies for indoor use where high chemical resistance isrequired and acrylics and polyesters including epoxy-polyester hybridsfor outdoor use where superior UV resistance is needed. In typicalpowder coating operations, the object to be coated is suspended in afluidized bed or subject to an electrostatic spray so that particlesflowing past this object may stick on its surface (where the particlescontact and melt due to higher surface temperature or the particles areattracted due to the static attraction and melted later). Typically, thepowders melt and then cure forming a coating. The coating processingtemperatures are typically in the range of about 80 to 200° C. In thepast, mainly metals were coated with polymeric powders. Recently,however, increasing use is being made of polyurethane powders forcoating objects made of thermoset polymers and acrylic powders forcoating thermoplastics objects (including acrylics which are cured usingUV after the coating is deposited).

To produce powder coatings, one may prepare powders of functionalizedantimicrobial particles or incorporate antimicrobial particles in porousmaterials (such as porous silica) and then dry blend with powder coatingresins. Other ingredients such as crosslinking agents, degassers(defoamers) and flow additives may also be added to this blend, which isthen mixed in an extruder where the resin melts and is the compositionis extruded, and the material pulverized to form a powder. This powderis then used to coat the objects (e.g., by a corona gun) and then heattreated to fuse the powder on the substrates which results in anantimicrobial coating.

The materials of the present invention may also be incorporated inanodized coatings to provide antimicrobial characteristics in additionto the wear and corrosion resistance which these coatings impart to thesurfaces. Anodization is used to coat/treat many metals and is mostoften used for magnesium, aluminum and their alloys. Anodization is anelectrochemical process, wherein the metal object or substrate iscleaned and placed in the electrochemical bath, which is typicallyacidic. There are several variations where organic or inorganic acidsare used for this purpose and are well known in the art. The typicalthickness of anodized layers is in the range of 0.5 to 150 μm. Onemethod to incorporate the antimicrobial materials of this inventioninvolves treating the anodized objects with solutions of functionalizednanoparticles of the antimicrobial agent so that they can penetrate theporous structure of the anodized layers and get trapped in the interiors(anodized coatings are usually porous with a pore size of 5 to 150 nm).Another method involves incorporating the functionalized antimicrobialparticles during the process of anodization. In this process, theantimicrobial nanoparticles are typically functionalized with acids oreven acidic polymers such as polystyrene sulfonic acid and then suchfunctionalized particles are added to the anodization bath. Suchfunctionalization imparts negative zeta potential to the particles sothat they have sufficient mobility in the applied field towards theanode and get incorporated within the anodized coatings as thesecoatings form on the surfaces of the objects being anodized.

Other embodiments of products formed from the antimicrobial compositionsof the present invention include topical creams for both pharmaceuticaland consumer product use (e.g., personal care products). They can impartone or both of antimicrobial and preservative properties. As a specificexample, functionalized particles may be added to/formulated withCarbopol® polymers from Lubrizol to produce gels and creams which may beused as antimicrobial creams for treatment of bacterial and fungalinfections, wounds, acne, burns, etc. Although any concentration of thefunctionalized nanoparticles may be used which provides effectivetreatment, a useful range of metal concentration (from the surfacefunctionalized particles) in the finished product is 10 to 50,000 ppm.The precise concentration of any particular topical treatment can beassessed by testing the cream in any of the assays for antimicrobialeffect presented herein, or known to one of ordinary skill.

The functionalized antimicrobial particles may also be formulated inpetroleum jelly to provide superior water resistance. One may useadditional surfactants and compatibilizers so that while the hydrophobicpetroleum jelly protects the application area, it is also able torelease the antimicrobial material to the underlying areas which may behydrophilic. One of ordinary skill in the pharmaceutical art ofcompounding will know how to create antimicrobially active creams andointments in combination with the functionalized metal halide powders ofthe present invention. As an example, one may formulate the materialsusing PVP/Polyolefin copolymer as functionalization agents which areavailable from Ashland (New Milford, Conn.) as Ganex® WP-660, Ganex®V-516 and Ganex® P904LC with various levels of olefinic content andhydrophobicity. One may optionally add hydrophobic esters for thereasons as described earlier, some examples are ascorbic acid palmitateand lauryl gallate.

One may also fabricate antimicrobial sutures and wound dressings(including burn dressings) using the materials of the present invention.Dressings consisting of gauze (textiles) or foams or sutures may be madeby incorporating the functionalized antimicrobial particles of thisinvention into the constituent fibers or materials of these dressings orsutures. Antimicrobial dressings may also be formed by soaking gauze,fabrics and foams in aqueous solutions containing functionalizedparticles and a hydrophillic polymer (e.g., PVP, carboxy methylcellulose, etc.). For those dressings which use cuprous salts, additivesto keep cuprous ions from oxidizing are also preferred. The wounddressings may be formed by laminating various layers where each layerprovides different functions. In some cases only some of the layerscontain antimicrobial agents. The feel or the drape of the dressings andtheir adhesion properties to the wounds may be modified by addingnon-toxic surfactants, glycols, fatty acids and oils, etc. to thesolution compositions. These dressing may have other medications oradditives also incorporated in them (e.g., analgesics) in a posttreatment or by adding them to the same solution which contains theantimicrobial particles. Additives also include iron sequestering agentsso that they would reduce the availability of iron for bacteria to growand produce biofilms. Some of these agents are phosphates withpreferential sequestering of iron, glycol proteins such asovotransferrin, lactoferrin and sertotransferrin. Additives may alsoinclude more water soluble salts to provide immediate release, ofantimicrobial anions or cations or both, e.g., these salts may be CuCl₂,AgNO₃, KI, NaI, etc. The additives may further include materialscompatible with the mucus agents which form the biofilms, so as to helpwith the transport of the antimicrobial materials through these biofilmsto deliver the antimicrobial agent to the surfaces of the bacteria orspores. Examples of some materials with such characteristics includeglucose and xylitol. In addition these materials are also known tostabilize the oxidation state of metal (e.g., Cu⁺) ion. These may bealso incorporated as functionalizing agents. To make wound dressingswith broader efficacy, one may combine more than one type of metal saltor use solid solutions of metal salts. For example, some preferredcombinations are CuI with AgBr, CuI with AgCl and CuI with AgI. Thesedressings may have several components as discussed above in order toprovide antimicrobial properties and other wound management attributes,some additional components are discussed below, such as water solublehalide salts. These dressing may be a part of one or more of the layersof a flexible multilayer wound dressing laminate, wherein preferably thelayer in contact with or close to the wound contains the antimicrobialmaterial.

Another embodiment of the functionalized metal halide particles isdirected to an antimicrobial composition for wound management,comprising a povidone-iodine solution and at least one type offunctionalized antimicrobial particle having an average size of fromabout 1000 nm to about 4 nm. A further embodiment of the povidone-iodinesolution is wherein the antimicrobial particle is selected from thegroup consisting of copper halide and silver halide, and a furtherembodiment comprises halides selected from the group consisting ofiodide, chloride and bromide, and a still further embodiment comprisesCuI. The povidone-iodine compositions of the present invention may alsobe used to treat animals or humans to treat infected topical areas. Asone example, aqueous topical solutions of PVP and iodine (where iodineis about 8 to 12% by weight of the PVP) are commonly used asdisinfectants for wounds and for disinfecting skin prior to surgery.BETADINE® is a commercially available PVP-iodine solution.Povidone-iodine (PVP-I) is a stable chemical complex of PVP andelemental iodine. 10% solutions in water are commonly used as a topicalantiseptic. One may add the functionalized antimicrobial particles ofthe present invention (such as AgI and/or CuI particles functionalizedwith PVP) to such PVP-iodine solutions to obtain new disinfectantsolutions with notably enhanced disinfecting ability. Compositions ofmetal halide particles added to such PVP-I solutions also come withinthe scope of the current invention. Such a metal halide-enhanced PVP-Isolution would be formulated having about 88-99% PVP, 2 to 10% Iodine,and 0.005-10% metal halide particles on a wt/wt basis. One may also addadditional water soluble halides such as KI, NaI, LiI to theantimicrobial formulations, and their typical molar concentration ratiois about 0.001 to 0.1 as compared to concentration (molar) of the metalhalides in the formulation. One method to make such compositions is bywet-grinding the metal halide(s) in PVP-I solution for surfacefunctionalization of the particles being ground, where we have foundthat while grinding CuI, NaI functions as a grinding aid in presence ofPVP, and thus it is preferred that this be added before or during thegrinding operation. These weight proportions are relative to these threecomponents excluding water and other solvents.

For wound management (creams and dressings) the functionalized particlecompositions may comprise additional additives. These additives arehelpful in maintaining pH (buffers to control pH in the range of 4 to 7)and also increase the efficacy of such compositions. The preferredadditives are reducing agents (antioxidants) such as organic acids,aldehydes, alcohols and their salts. Some of the preferred acids andtheir salts are citric acid, ascorbic acid, cinnamic acid, hyaluronicacid, salts of these acids, and preferably lithium, sodium, potassium,calcium, copper and silver salts of these acids. Some acids which haveseveral groups may be converted to the salts by substituting one or moreof these groups. As an example, citric acid can be converted to sodiumcitrate by reaction with a sodium-containing base. In this way one canform monosodium, disodium and trisodium citrates or their mixtures. Anyof these may be used, but trisodium citrate is preferred for wounddressings and creams when used with functionalized metal halideparticles, particularly copper and silver halides. A preferredfunctionalization for these halide particles are polymers used inconjunction with soluble halide salts (such as LiI, NaI and KI). Thepreferred polymers are those with mildly reducing properties such asPVP, copolymers containing PVP (i.e., copolymers containing vinylpyrrolidone groups) and carboxy methyl cellulose.

The antimicrobial materials of this invention may also be used asadditives to other drug formulations including other antibiotic creamsor formulations for infection control or related purposes. Theantimicrobial materials of this invention may be added in a burn cream,which while assisting the repair of burned tissue will also keepinfection away, or it may be mixed with other antibiotics, infectionreducing/prevention analgesic materials such as bacitracin, neomycin,polymyxin, silver sulfadiazine, polyenes, selenium sulfide, zincpyrithione and paramoxine, Many of these compositions listed above areavailable in commercial products, and the antimicrobial materials ofthis invention can be added to them to result in a concentration that ismost effective.

The compositions of the present invention can also contain anycombination of additional medicinal compounds. Such medicinal compoundsinclude, but are not limited to, antimicrobials, antibiotics, antifungalagents, antiviral agents, anti thrombogenic agents, anesthetics,anti-inflammatory agents, analgesics, anticancer agents, vasodilationsubstances, wound healing agents, angiogenic agents, angiostatic agents,immune boosting agents, growth factors, and other biological agents.Suitable antimicrobial agents include, but are not limited to, elementaliodine, biguanide compounds, such as chlorhexidine and its salts;triclosan; penicillins; tetracyclines; aminoglycosides, such asgentamicin and Tobramycin™; polymyxins; rifampicins; bacitracins;erythromycins; vancomycins; neomycins; chloramphenicols; miconazole;quinolones, such as oxolinic acid, norfloxacin, nalidixic acid,pefloxacin, enoxacin, and ciprofloxacin; sulfonamides; nonoxynol 9;fusidic acid; cephalosporins; and combinations of such compounds andsimilar compounds. The additional antimicrobial compounds provide forenhanced antimicrobial activity. Some of these may be treat humans oranimals as a whole (e.g., by oral administration, injection, etc).

Several antimicrobial treatments may require use of sprays (e.g.,aerosol spray-on bandages or topical treatments of infections), or evenspray-on paints and household cleaners. In many of these cases, it isnot desirable to have very small functionalized particles present inthese compositions, since during the spray operation, many of theparticles could become airborne and enter the human airways. There areseveral ways of overcoming this while using the antimicrobial materialsof the current invention in the nanoparticle form. One method is to formclusters of functionalized nanoparticles typically larger than 1 micronwhich keep their togetherness by using a binder which does not allow thenanoparticles to come apart in the spray solvent, For example, thebinder may be water soluble while the solvent for the spray (e.g.,dimethyl ether, CF₃CHF₂, CF₃CH₂F) would be a non-solvent for the binderand would keep the clusters intact. Another method involves infusing theparticles in non-ion exchange porous particles which are greater thanabout 1 micron in size (as discussed in an earlier section) andincorporate these particles in the aerosol medium. Yet another methoduses particles which are greater than 100 nm in size.

In cases where it is desired to use functionalized antimicrobialparticles in the treatment of lung infections, it is preferred to employparticles with substantial water solubility combined with water-solublefunctionalizing agents. In this way, aerosols can be prepared using anebulizer and delivered to the patient's lungs to provide the desiredhigh dose of antimicrobial activity, and over reasonable periods of timethe particles will be eliminated by dissolution. In cases where deeppenetration of the antimicrobial agent into the airways is desired, useof small nano-sized particles may be desirable.

Other embodiments of the present invention comprise medical devices thatare rendered antimicrobial using methods comprising contacting thesurfaces of the devices with the functionalized salt compositions of theinvention. Medical devices, without limitation, include catheters(venous, urinary, Foley or pain management, long dwell catheters orvariations thereof), stents, abdominal plugs, pacemakers, hearing aids,masks (including ventilators), cotton gauzes, fibrous wound dressings(sheet and rope made of alginates, CMC or mixtures thereof, crosslinkedor uncrosslinked cellulose), collagen or protein matrices, hemostaticmaterials, adhesive films, contact lenses, lens cases, containers forcleaning solutions, bandages, sutures, hernia meshes, mesh based woundcoverings, ostomy and other wound products, breast implants, hydrogels,creams, lotions, gels (water based or oil based), emulsions, liposomes,ointments, adhesives, porous inorganic supports such as silica ortitania and those described in U.S. Pat. No. 4,906,466, the patentincorporated herein in its entirety by reference, chitosan or chitinpowders, metal based orthopedic implants, metal screws and plates etc.

The compositions of this invention may be added into the resin fromwhich the products are made and then extruding or molding these objects,or they may be added as coatings. One may prepare the antimicrobialfunctionalized metal salt particles by any one of the disclosed methods,and then redisperse them in a liquid medium and apply them to thedesired substrate. Alternatively, as discussed in an earlier section,one may use solutions of metal salts such as metal halides withfunctionalizing agents to form coatings or impregnate objects such aswound dressings.

The compositions of this invention may also be used for toothrestoration. These include applications such as dental adhesives,primers, sealants and composite fillings and products such as dentures(including antimicrobial solutions to treat dentures), crowns, bridgesand coatings including coatings on implants. The methods ofincorporating the antimicrobial agents of this invention in solutions,sealants/adhesives and coatings for dental applications are very similarto those employed for other applications discussed throughout thispatent application. As an example, in several dental sealants andadhesives the surfaces bonded are dentin while in some others these areenamels. It is important for the antimicrobial materials which contactthe dentins are biocompatible with such surfaces. Some of the standardmaterials used in restorative composites are UV cured resins comprisingmethyl methacrylate, 2-hydroxyethyl methacrylate urethane dimethacrylateoligomer, bisphenol A-glycidyl methacrylate. triethyleneglycolmethacrylate, ethyleneglycol dimethacrylate and silanes are also usedfor adhesion promotion. One may use particles of this invention wherethe functionalization agents are chosen from the above materials, as anadditive to the dental compositions. Alternatively porous particlesformulations as discussed earlier may also be used.

Yet another application of these materials involves the production ofhousehold and industrial disinfectants. Depending on the composition ofthe disinfectants, they may provide a rapid kill when these contact orare sprayed onto surfaces. After wiping the treated surfaces, thedisinfectants may be formulated to leave a residue which will providecontinuing protection against microbes which subsequently contact thesurface.

Rapid kill is typically less than 5 minutes, preferably less than twominutes and most preferably 30 seconds or less. This is achieved byincluding in the formulation components in a concentration which killmicrobes rapidly. Many of these components may be combined to producesynergistic effects, while keeping the concentration of each of theselow. Such components typically result in a rapid change in pH, hydrationor damage to the protective microbe membrane. These include acids suchas acetic acid, citric acid, alcohols and ethers such as isopropanol,ethanol and propylene glycol monobutyl ether, quaternary ammoniumcations including silanized versions, water soluble salts of activecations such as silver and copper, and certain functionalized particlesof this invention. Long-time protection is typically greater than twohours, preferably greater than 24 hours and most preferably greater than1 week. Such long term protection is provided by formulating thedisinfectants with appropriate concentrations of functionalizedparticles together with a film-forming polymer or polymers.

The preferred disinfectant formulations are aqueous based, with a pH inthe range of about 2 to 7. The pH may be controlled by acids andbuffering materials. Some of the preferred acids and their salts areacetic acid, citric acid, ascorbic acid and cinnamic acid and salts ofthese acids for buffer control. Some of the preferred salts are lithium,sodium, potassium, calcium, copper and silver salts of these acids.Particularly preferred acids include acetic acid and citric acid.Particularly preferred salts include sodium and potassium salts of theseacids.

The disinfectants may also include surfactants, alcohols, and ethers toclean fatty residues from the surfaces to which they are applied andalso to provide better wetting of the surfaces (e.g., isopropanol,ethylene glycol monohexyl ether, sodium lauryl sulfate, etc.). Thesematerials may also be used as functionalizing agents.

The film forming polymers used in the disinfectant formulations includePVP, copolymers comprising PVP, chitosan, ionic polymers (e.g., anionicpolymers comprising carboxylic or sulfonic acid groups and their saltswhere the protons are substituted by lithium, sodium, potassium, etc).These polymers may be used both as functionalization agents and as filmformers. The resulting films maintain a fraction of the antimicrobialparticles trapped in the coatings on the surfaces after the liquidcarrier has evaporated. Examples of other additives are viscositymodifiers, soluble salts, fragrances, colorants and compounds to promoteantimicrobial ion stability.

As another example, the compositions of this invention may be includedin hair care products or other body care (personal care) products suchas antidandruff shampoos, body washes, deodorants, nail polish andmoisturizing and other creams. In such cases, one may grind theparticles using the matrix compositions of the respective formulationsas the grinding fluids. One may also carry out the grinding in adifferent medium (e.g., an aqueous medium containing a surfactant,dispersant or a polymer used in the product formulation), and addingthese suspensions to the end products.

Yet as another example, pet products such as toys, treats (e.g. chews)and food items (e.g. kibbles) may have the antibacterial compositions ofthis invention coated or infused within these products. Many of theseproducts are recalled for bacterial infection, particularly Salmonella.As a specific example, many pet chews are made from animal hide or pigears. These products are processed by washing hides/pig ears in hotwater and then shaping and drying them at about 80 to 90 C for a periodof about 20 to 48 hours. Although the hot water baths and dryingprocedures are expected to kill many of the bacteria, it is possiblethat some spores may survive or the product surfaces pick up infectionfrom surfaces they contact in post processing operations. One treatmentmethod comprises adding the compositions of this invention in the lastaqueous bath so that these infuse into the products before they aredried. Alternatively these products may also be sprayed with the presentantimicrobial compositions. Such treatments will not only kill residualbacteria, but also stop bacterial colonies from growing if the productsurfaces are later come in contact with microbial contamination. Whenusing functionalized copper salt particles, their concentration in thebath could be any; but a preferred range is about 1 to 500 ppm (measuredas copper concentration). It is further preferred that the overallcopper salt (e.g. CuI) concentration in a chew or a food product istypically less than 0.01% by weight, although the surfaces of theseproducts may have higher concentrations. When functionalized metal saltparticles are used some of the preferred functionalization agentsinclude amino acids, carbohydrates and PVP. The functionalizedantimicrobial particles of the present invention can also be added tobaste formulations used in manufacturing pet products, so that coatingsof these on the pet products also provide benefit of antimicrobialprotection in addition to other attributes. For incorporating thedisclosed materials in polymers used either for packaging or in pet toysone can follow the methods used for as discussed earlier for bulkpolymers where masterbatches were discussed.

Also contemplated by the present invention are antimicrobial fabrics(including carpets), such as those based on synthetic fibers, e.g.,nylon, acrylics, urethane, polyesters, polyolefins, rayon, acetate;natural fiber materials (silk, rayon, wool, cotton, jute, hemp orbamboo) or blends of any of these fibers. The fibers or yarns may beimpregnated with suspensions of the functionalized antimicrobialparticles, or for synthetic fibers the functionalized nanoparticles maybe incorporated into resin melts/solutions (e.g., using the masterbatchapproach discussed earlier) that are used to form the fibers. In analternative embodiment, the fabrics may be provided with coatingscontaining the antimicrobial compositions of the present invention.Devices, medical including dental and veterinary products andnon-medical, made of silicone, polyurethanes, polyamides, acrylates,ceramics etc., and other thermoplastic materials used in the medicaldevice industry and impregnated with functionalized particles usingliquid compositions of the present invention are encompassed by thepresent invention.

Various coating compositions for different polymeric, ceramic glass ormetal surfaces that can be prepared from liquid compositions are alsocontemplated by the present invention, as are coating compositions whichare impregnated with functionalized antimicrobial particles after theirdeposition. Metal alkoxides and other metal oxide precursors (e.g.,metallo-organic, water soluble silicate, aluminate, titanate andzirconate, mixed metal precursors such as alkoxy aluminum silicates,etc) may be used to form porous ceramic/glass coatings. In oneembodiment, the antimicrobial metal salts functionalized by metal oxideprecursors (including porous particles of metal oxides with infusedmetal salts) may be added to coating solutions formed by metal oxideprecursors. In some cases both the precursor used for functionalizationand for forming the coating may be similar for enhanced compatibility.The coating compositions deposited from liquid solutions can be hardenedby solvent loss or cured by thermal or radiation exposure or byincorporation of polymerization (e.g., cross-linking) agents in thecoating formulations. The resulting coatings may be hydrophobic,oleophobic (or lipophobic) or hydrophilic. The oleophobic coatings aretypically used on display screens, particularly touch screens andimparting of an antimicrobial character to such surfaces can bevaluable. Further for touch screens the coatings should be transparentand abrasion resistant.

Antimicrobial medical and non-medical devices of the present inventioncan be made by treating the devices with the functionalized metal saltcompositions of the present invention by different methods. Onedisclosed method of the present invention comprises the steps of makingthe compositions in a dry particulate form that may be redispersed in anaqueous or nonaqueous carrier liquid, then contacting the compositionsand the device surfaces for a sufficient period of time to allowaccumulation of particles and then rinsing the excess of saidcomposition away and drying the device. A modification of the disclosedmethod may involve drying or curing the surface of material first andthen rinsing off the surface to remove excess. The method of contact maybe dipping the device in the compositions or spraying the compositionson the device or coating blends of polymer solution and thecompositions.

In other cases, the functionalized antimicrobial particles or porousparticles containing antimicrobial compounds may be incorporated inpolymer-based coating solutions from which antimicrobial coatings aredeposited by end users. For example, the compositions of the inventionmay be applied to marine surfaces as a bactericidal agent. As anotherexample, the compositions of the invention may be incorporated inpolyurethane coating solutions and applied to furniture or flooring bythe end users.

In another aspect, the present invention provides methods andcompositions for applying antifouling coatings to an article such as aboat hull, aquaculture net, or other surface in constant contact with amarine environment. Materials that are immersed for long periods of timein fresh or marine water are commonly fouled by the growth ofmicroscopic and macroscopic organisms. The accumulation of theseorganisms is unsightly and in many instances interferes with function.The natural process of accumulated growth is often referred to asfouling of the surface. There are a number of agents that may be appliedto the surfaces to inhibit this growth, and may usefully be combinedwith the materials of this invention. These agents are known in the artas anti-fouling agents. While many of these agents are highly effective,some of them may be toxic that often leech from the surface of thearticle and accumulate in the local environment. In one embodiment, thepresent invention provides a composition for treating a marine surfacecomprising a particle having at least one inorganic copper salt, and atleast one functionalizing agent in contact with the particle, thefunctionalizing agent stabilizing the particle in suspension such thatan amount of ions are released into the environment of a microbesufficient to prevent its proliferation.

Another application of the present inventions involves stopping theproliferation of microorganisms and the resultant formation of slime(biofilm) in “aqueous systems”. The materials of this invention areparticularly effective when the pH is acidic or has reducingcharacteristics, or alternatively the metal halide particles arefunctionalized with such materials and then incorporated in coatings orin bulk. The microbes of concern include bacteria, fungi, and algae. Therelevant “aqueous systems” include both industrial and residentialapplications. Examples of these application include water coolingsystems (cooling towers), pulp and paper mill systems, petroleum (oiland gas) operations, water and slurry transportation and storage,recreational water systems, air washer systems, decorative fountains,food, beverage, and industrial process pasteurizers, desalinationsystems, gas scrubber systems, latex systems, industrial lubricants,cutting fluids, etc.

In petroleum applications, particularly in oil and gas extraction,transportation, storage and further processing (i.e., collectivelycalled petroleum extraction industry), antimicrobial materials (orbiocides) are used in injection fluids, e.g., hydraulic fracturingfluids (also called fracking fluids) and/or breaking fluids typicallyused for oil and gas wells. Injection fluids are also used to deliverbiocides in the wells on a regular basis (e.g. daily or a weekly) inorder to control bacteria, corrosion and formation of slimes due tobacterial growth in these wells. Drilling fluids also use biocides.

The bacteria of concern may be aerobic (e.g., Pseudomonas aeruginosa andStaph. aureus) or anaerobic (e.g., sulfate reducing bacteria (SRB) andacid producing bacteria (APB)). Generally one finds mixtures of bacteriaand biofilms of multi-species bactreria in oil wells including,heterotrophic bacteria as well as SRB and APB. Anaerobic bacteria arealso found in various waste water streams. Thus the antimicrobialcompositions of the present invention may also be used in the wasteprocessing industry where waste water is collected or processed.

The biocides should be compatible with the other additives which areincluded in the fluid compositions. Some of the additives used in fluidsfor this application besides biocides such as gluteraldehyde and quatinclude scale and corrosion inhibitors (e.g., ethylene glycol),viscosity modifiers (e.g., polyacrylamide), emulsion breakers (e.g.,ammonium persulfate), acids to dissolve minerals (e.g., hydrochloricacid), organic acids to avoid iron precipitation so as to reduce scaleformation (e.g., citric acid), gelling agents (e.g., guar gum), claystabilizers (e.g., potassium chloride), oxygen scavengers (e.g.,ammonium bisulfate), pH control agents (e.g., carbonates of potassiumand sodium), proppants (e.g. sand) and surfactants (e.g. sodium laurylsulfate, isoproanol).

The functionalized particles of this invention may be used as a total orpartial replacements of the biocides used in the fluids in order tolower the toxicity of the fluids, and still provide superiorantimicrobial properties. It is highly preferred that such particles arepre-formed and added to these fluids and remain in particulate form inthe fluids at the time of injection. In order to increase thecompatibility of the functionalized particles with these fluids, one mayuse one or more of the components already present in the fluid asfunctionalization agents—e.g., polyacrylamide, organic acids such asformic acid, acetic acid, citric acid, salts and esters of these acids,and also aldehydes such as gluteraldehyde, cinnamonaldehyde, ethyleneglycol, surfactants, etc.

The fluid compositions (including biocide chemistry and concentration)are customized depending upon the geographic location of the well, typeof operation and the function being carried out at that time. This isdue to different types of bacteria which may be present there; andwhether the bacteria need to be killed in planktonic form or alreadyexist in biofilm form; the speed at which the antimicrobial action isdesired (minutes, hours, days, etc); geological composition; and thetype of water being used. For example, one may use sea-water or freshwater; and the desired characteristics of the biocide may be differentfor a hydrofracking operation where a relatively rapid biocidal actionis desired, vs. periodic biocide treatment of a well where a slower buta longer lasting biocidal action is desired.

When particles of the present invention are employed in fluidformulations used for fracking and are present alongside of the proppantparticles (also present in these fluids), they provide antibacterialproperties over a long period of time by limiting biofouling of thefissures formed in the fracking process. When particles of thisinvention are used in fluid formulations with proppants, their averageparticle size should preferably be similar to but somewhat smaller than(as about 10-25% smaller than) the size of the proppants. One may evenuse more than one size of antimicrobial particles so that these would betrapped at different places in the oil field/well. The particles mayalso be sized and functionalized so that they are attracted tp andtransported into the already formed biofilms, and then kill the bacteriain these biofilms. One may also use particles of different sizes anddifferent functionalizing agents so that some of these are designed tokill the bacteria more efficiently in planktonic form and others inbiolfilm form.

The materials of the present invention when added to such fluids areeffective at low metal concentrations; and as discussed above differentapplications within the petroleum industry may require differentconcentrations. A preferred range of concentrations expressed as metalconcentration of the antimicrobial material is preferably in the rangeof 1 to 1,000 ppm.

One may also use antimicrobial additives in compositions used to coatpipes, storage tanks, valves, probes (sensors), or used as liners, orother service components in the petroleum extraction industry or otherindustries where prevention of bacterial biofouling (slime) isimportant. These single or multilayer coatings and liners may comprisepolymeric or glass matrices such as epoxy, polyolefins, urethane,alkyds, acrylic, polyester, silica and silicates. These coatings may bedeposited from liquid formulations or may be fusion bonded (powdercoatings). In these coatings (or at least in one of the layers of amultilayer coating system), the weight fraction of the active materials(e.g., copper salts) of this invention may be any, and is preferablylower than lower than 5%. The biocides of this invention preventbacteria from proliferating in wells, pipes, and storage tanks, andspecifically control or reduce the formation of bacterialbiofilms/slimes on their surfaces. They also prevent the release of foulsmelling gases (e.g. hydrogen sulfide) by SRB & the corrosion of ferrouspipes and tanks with the formation of iron sulfide. Thus the addition ofthe materials of this invention also helps with corrosion control ofiron and steels components. The antimicrobial materials may also beincorporated in the bulk of materials (e.g., plastics) used to makecomponents for the industry.

These compositions, particularly those which comprise CuI can also workas corrosion inhibitors even in the absence of anaerobic bacteria. Inthe past it has been shown that CuI imparts corrosion resistance toferrous metals at high temperatures. For example, in U.S. Pat. No.3,773,465, CuI is combined with an efficient corrosion reducer underhighly acidic conditions—e.g., using 15-30% HCl. If other corrosioninhibitors are not included even at use levels of 2.5% or 25,000 ppm ofCuI, the treatment is not effective for corrosion control. There is nohint in this patent on any effect of CuI on bacteria. The teachings ofthis patent are consistent with the general knowledge that “Copperiodide is used in acid muds to bind corrosion inhibitors to the irondrills” (Richardson, Wayne H., Chapter on “Copper compounds” inUhlmann's encyclopedia of Industrial Chemistry, Vol 9, (2003) p473-502). It should also be noted that when one adds 1,000 ppm copper ascopper iodide (which means 3,000 ppm of copper iodide) to 15 or 30% HCl,a clear liquid is formed. This shows that the CuI has completelysolubilized or reacted to form products which are soluble. Thus theaddition of CuI particles to highly acidic systems will result in theirdissolution, and the injection liquid or the product of manufacture willnot comprise functionalized particles.

When large quantities of water are used, the use of such acidicformulations is not practical. Hydraulic fracturing of a single well mayrequire 10 million liters of water (and 10 to 15 such operations may berequired during the operation of the well). Even the use of HCl at aconcentration of 5% results in a water pH of 1.9, and higher amounts ofacid will lead to lower pH's. When large amounts of water are injected,it is important that the toxicity of such aqueous formulations be low,and the pH be above 2, preferably above 4, and more preferably above 5.When using the functionalized particles of the present invention asbiocides in petroleum extraction operations the copper concentration thefluids associated with the added CuI particles should preferably be lessthan about 1,000 ppm, more preferably less than about 150 ppm and mostpreferably less than 60 ppm. The particles of this invention can becombined with known corrosion inhibitors (e.g., glycols such as ethyleneglycol, Mannich reaction products, quaternary amine compounds and theirmixture, e.g., also see published US patent application 20110100630);and when this is done, use of the particles of this invention makes itpossible to use lower concentration of corrosion inhibitors. One mayalso use corrosion inhibitors as functionalizing agents.

Applications of the above teachings is not limited in petroleum (oil andgas) industry, as applications encompass various chemical and industrialprocesses where corrosion and slime formation or health issues due toanerobes or aerobic bacteria is important.

Yet another application of the present invention is to situations wherehuman waste is collected for a period of time before it is disposed—forexample, in waste control in portable toilets. Such toilets areextensively used to provide facilities for temporary use such as inconstruction and other military and civilian activities, and theapplication also includes toilets used in the transportation industrysuch as planes, buses, trains, boats, ships and space travel. In theseapplications, it is important to control microbial proliferation in thetanks holding such wastes for days to months. The antimicrobialparticles of this invention may be added to the contents of these tanksas additives and/or may be incorporated in coatings on the interior ofthe tanks One may also incorporate the antimicrobial materials indisposable liners in these tanks. One may also add the antimicrobialmaterials of this invention introduced in porous or permeable cakeswhich may be added to the tanks, or to the flushes of toilets (portableor non-portable types) so as to provide antimicrobial ions into thewater body for a long period of time (or/and multiple flushes).

Another example is incorporation of the materials of this invention inpersonal care (or body care) products. A non-exhaustive list of theseinclude nail polish, shaving creams, shampoos, hair detanglingsolutions, hair gels and colorants, deodorants, toothpaste,toothbrushes, mouthwash, body creams ((including moisturizing and antiwrinkle creams), powders, mascara, blush, foundation, and othercosmetics, etc. Many of these formulations use preservatives such asparabens to ensure that the product has long life and that any bacterialcontamination carried into the container from an applicator (e.g.,brush) or by reintroducing the unused product by the user does not endup multiplying and then pose a hazard. The antimicrobial materials ofthe present invention may be used to replace parabens in cosmetics andbody care products. Brushes and pads (e.g. foams) used to apply theseproducts may also comprise antimicrobial materials of the presentinvention. These antimicrobial materials may be incorporated within thefibers which are used in making these brushes (including toothbrushbristles) or may be applied as coatings on these fibers. Similarly inpads they may be incorporated in the bulk of the materials to make thesepads or incorporated as coatings on surfaces. For example open cellfoams used for these applications may be treated withsolutions/suspensions of the antimicrobial materials to coat the poresurfaces.

Antimicrobial applications include their use in construction materials,including wood preservatives, mold and mildew resistant products, andanti-fouling in other building and construction products such asnon-fluid (including dry walls, insulating materials, faucets, sinks,toilet and other bathroom and kitchen products) and fluid productsincluding paint, adhesive and caulks. This protection may be imparted tothe fluid products while many of these products are in the containers(as preservatives) and/or they continue to have antimicrobial propertiesafter they are applied in the field.

Applications include formulations comprising materials of this inventionin formulations for treatment of water bodies for microbial and also foralgae control; these include aquaculture facilities, fountains, lakes,reservoirs (crop and non-crop irrigation, potable), stocking (tank,water trough and ponds) and irrigation canals, drainage systems (canal,ditch and lateral), ponds (farm, industrial and recreational) sewagelagoons. The materials of this invention may be applied as coatings, asliquid suspension additives to the water bodies, or as porous orpermeable cakes which will continue to elute the antimicrobial materials(or ions) for a long time.

Applications also include use in formulations for agricultural uses suchas all food/feed crops; this includes orchard, row, field, and aquaticcrops. The formulations of this invention may be applied by sprayingfrom aqueous suspensions. Some examples of crops include: root andtubers, bulb vegetables, leafy vegetables (including brassica), fruitingvegetables, citrus, pome fruit, stone fruit, legumes, berries,cucurbits, cereals and tree nuts, ornamental crops, which includesflowering/non-flowering plants and trees. In addition uses also includewash treatments for fruits and vegetables to get rid of the microbes andother pests. One of the preferred methods of adding the metal saltparticles (e.g., CuI) of the present invention is by producingfunctionalized particles using surface functionalizing agents which arealready present as ingredients in the product. These functionalizingagents may be derived from natural sources (e.g. vegetable extracts) orformed synthetically. A non-exhaustive list of some of the materialsused in body care products for functionalization is given in the sectionlabeled “Functionalization agents”. A preferred way to functionalize theparticles is to grind the antimicrobial material (e.g., metal salts suchas metal halides) in presence of these surface functionalizing agents asalso described in the section on “Formation of functionalized particlesby grinding”. Typical concentration levels of antimicrobial halides arepreferably less than 1% and more preferably less than 0.1% (ascalculated based on the weight of the metal from the antimicrobial metalsalt to the total formulation weight).

In many of these examples, the materials of this invention may becombined with other known antimicrobial materials used for thatparticular application.

As shown in numerous examples the materials of this invention may beadded to any liquid or solid products to impart antimicrobialproperties. Liquids include high viscosity and/or thixotropic liquids orany of those soft materials which will show predominantly viscous flow.Examples of high viscosity liquids at room temperature are body creams,ointments, toothpaste, deodorant sticks, uncured caulking material, waxypolishes, etc. Solid materials (including coatings) are typically ableto support their weight and the soft materials upon deformation are ableto regain their original shape. Examples of solids which are soft atroom temperature are elastomers, foams and any other deformable bodieswith chemical and physical crosslinks, etc.

Although the primary application of the functionalized salt particles ofthis invention are for antimicrobial agents, in several cases their usecan be extended to other uses, where they show a superior effect ascompared to the use of the same salts but where the particles are notfunctionalized. In addition functionalized particles of these salts mayalso be made inexpensively by grinding processes. These may be used asadditives for improving thermal stability of nylon resins (e.g., nylon6; nylon 6,6; nylon 6,10, etc.); catalytic agents for chemicalreactions; improve both the processability and the properties ofsemiconductors made from metal salts; and finding drugs and/ortreatments for those medical treatments which are not microbial innature, such as in anticancer (or tumor reduction) agents.

Functionalized particles of compounds of this invention hold greatpromise for the future of cancer therapeutics. Some of thefunctionalized particles of these compounds under defined conditionsinduce apoptotic cell death, believed through the generation ofintracellular reactive oxygen species (ROS). During one study, theseparticles elicited a dose-dependent decrease in cell viability.Oxidative stress is often hypothesized to be an important factor incytotoxicity of many types of cells. The uptake of these particles canbe enhanced through specific functionalization or active targeting forcancer cells. If designed appropriately, these particles will act as adrug vehicle able to target tumor or diseased cells and tissues. Throughthis functionalization it is believed that these particles can increasethe selectivity for killing cancer cells and decrease the peripheraltoxicity in healthy tissues and cells and allow for a dose escalation ofa therapeutic. The ability to tailor the chemical composition, size andsurface properties will allow for better pharmacokinetics properties.

The antimicrobial materials of the present invention may also be usefulin preventing so-called mad cow disease. The prions responsible for thisdisease are specific proteins which occur in specific conformations.Interaction of such proteins with the materials of this invention canresult in denaturation of the proteins with a change in theirconformation, rendering them innocuous.

For most applications, the range of addition of the inventive activeantimicrobial component (e.g., low solubility copper salt such as CuI)is about 0.001 to less than 5% by weight and preferably 0.001 to 3% byweight in the final end-use product. For those formulations wheresolutions (or suspensions) are used as end-use products, a preferredrange of the active antimicrobial component is below 3% by weight. Inorder to produce these commercial end-use products one may utilizeintermediate compositions, wherein the concentration of the activeantimicrobial component may be very high, e.g., in a range of 30 to 95%.Examples of these intermediate compositions are masterbatches,concentrated powder or liquid mixes, etc. These intermediates may beproduced in high concentration so that they can be easily transported,stored, and have characteristics so that they are easily miscible duringthe manufacturing of the final end-use products. As specific examples,these may be added to a resin on an injection molding machine beforemolding the end-use product, or to the resin before spinning the fibers,or to adhesive and caulking formulations, injection fluids in petroleumextraction, paint and coating formulations, etc. For those formulationswhich are dried by a loss of solvent (e.g., aqueous and solvent bornecoatings), the concentration of the active antimicrobial material iscalculated after drying. Preferred concentration range of the activeantimicrobial material in personal care products, disinfectants, etc.,is also below 5%, and preferably below 3%. In some applications higherconcentration of the active antimicrobial may be used. The followingexamples are illustrations of the embodiments of the inventionsdiscussed herein, and should not be applied so as to limit the appendedclaims in any manner.

4. Examples

Unless mentioned specifically in the examples, the followingmicrobiological processes were used for testing of antimicrobialsuspensions for efficacy against bacteria, mycobacteria, viruses, andfungi

a. Microbial Assays

The antimicrobial efficacy of the functionalized particles was evaluatedusing the following methods.

Maintenance and Preparation of Bacterial Isolates:

Test bacteria were obtained from the American Type Culture Collection(ATCC, Manassas, Va.) or The University of Arizona, Tucson, Ariz.:Escherichia coli (ATCC #15597), Enterococcus faecalis (ATCC #19433),Pseudomonas aeruginosa (ATCC #27313, ATCC #9027), Staphylococcus aureus(ATCC #25923), Mycobacterium fortuitum (ATCC #6841), Salmonella entericaserovar Typhimurium (ATCC 23564), and Streptococcus mutans (ATCC#25175). Escherichia coli 77-30013-2 (a copper resistant strain) wasobtained from Dr. Chris Rensing and Bacillus cereus was obtained fromDr. Helen Jost at the University of Arizona, Tucson, Ariz.

Bacterial isolates used in these studies were routinely cultured onTryptic Soy Agar (TSA; Difco, Sparks, Md.) at 37° C. or in Tryptic SoyBroth (TSB) medium at 37° C. on an orbital shaker at 200 r.p.m. In thecase of M. fortuitum, Tween 80 (polyethylene glycol sorbitan monooleate;Sigma Aldrich, St. Louis, Mo.) was added to the broth to a finalconcentration of 0.1% (v/v) to inhibit the formation of bacterialaggregates.

Preparation of Bacterial Spore Cultures:

One-liter cultures of B. cereus were grown in 2 L Erlenmeyer flaskscontaining trypticase soy broth (TSB; Difco, Sparks, Md.) inoculatedwith exponential-phase cells from trypticase soy pre-cultures. Thecultures were incubated at 37° C. on a rotary shaker at 200 rpm. Sporedevelopment was visualized by phase contrast microscopy. The cultureswere harvested after 72 hours. All harvesting and washing procedureswere performed at 25° C. Spores were harvested by centrifugation andresuspended with one-quarter culture volume of a solution containing 1MKCL and 0.5M NaCl. Centrifugation was repeated and cultures wereresuspended in one-tenth culture volume of 50 mM Tris-HCL (pH 7.2)containing 1 mg lysozyme/mL. Cell suspensions were then incubated at 37°C. for 1 hour followed by alternate centrifugation and washing with 1MNaCl, deionized water, 0.05% sodium dodecyl sulfate (SDS), 50 mMTris-HCl (pH 7.2), 10 mM EDTA, and three additional wash steps indeionized water. Spore suspensions were heat-shocked at 80° C. for 10min and stored at 4° C. until use (Nicholson, W. L. and P. Setlow. 1990.Sporulation, germination, and outgrowth. pp. 391-450. In Harwood, C Rand Cutting, SM (eds.) Molecular biological methods for Bacillus. JohnWiley & Sons, New York).

Maintenance and Preparation of Viruses:

Test viruses were obtained from the ATCC or Baylor College of MedicineHouston, Tex.: MS2 coliphage (ATCC #15597-B1) and Poliovirus 1 (strainLSc-2ab) Baylor College of Medicine Houston, Tex.

MS2 was maintained as described: Test tubes containing approximately 5ml of molten TSA containing 0.8% Bacto agar (Difco, Sparks, Md.) at 45°C. were inoculated with overnight cultures of E. coli and approximately1×10⁵ plaque forming units (PFU) of MS2. The molten agar overlaysuspensions were gently vortexed and poured evenly across the top of TSAplates and allowed to solidify. Following incubation of 24 hours at 37°C., 6 ml of sterile phosphate buffered saline (PBS; pH 7.4;Sigma-Aldrich, St. Louis, Mo.) was added to the agar overlays andallowed to sit undisturbed for 2 hours at 25° C. Following theincubation, the PBS suspension was collected and centrifuged (9,820× gfor 10 min) to pellet the bacterial debris. The remaining supernatantcontaining MS2 was filtered through a 0.22 μm (Millex; Millipore,Bedford, Mass.) sterile membrane pre-wetted with 1.5% beef extract andstored in sterile tubes at 4° C. until use. To determine the MS2 titer,the double-agar overlay method as described above was used; however,after the 24 hour incubation at 37° C., MS2 was enumerated by plaqueformation to determine the number of PFU/ml.

Poliovirus 1 (strain LSc-2ab) was maintained as described: Poliovirus 1was maintained in cell culture flasks containing BGM (Buffalo greenmonkey kidney; obtained from Dr. Daniel Dahling at the United StatesEnvironmental Protection Agency, Cincinnati, Ohio) cell monolayers withminimal essential medium (MEM, modified with Earle's salts; IrvineScientific, Santa Ana, Calif.) containing (per 100 ml total volume) 5 mlof calf serum (CS; HyClone Laboratories, Logan, Utah), 3 ml of 1 M HEPESbuffer (Mediatech Inc., Manassas, Va.), 1.375 ml of 7.5% sodiumbicarbonate (Fisher Scientific, Fair Lawn, N.J.), 1 ml of 10 mg/mlkanamycin (HyClone Laboratories, Logan, Utah), 1 ml of 100×antibiotic-antimycotic (HyClone Laboratories, Logan, Utah), and 1 ml of200 mM glutamine (Glutamax; HyClone Laboratories, Logan, Utah) at 37° C.with 5% CO₂.

Viruses were propagated by inoculating BGM cell monolayers. Followingthe observation of ≧90% destruction of the cell monolayer, the cellculture flasks were frozen at −20° C. and thawed three successive timesto release the viruses from the host cells. The culture suspension wasthen centrifuged (1000×g for 10 min) to remove cell debris, and thenprecipitated with polyethylene glycol (PEG; 9% w/v) and sodium chloride(5.8% w/v) overnight at 4° C. (Black et al. “Determination of Ct valuesfor chlorine resistant enteroviruses,” J. Environ. Sci. Health A Tox.Hazard Subst. Environ. Eng. 44: 336-339, 2009). Following the overnightincubation, the viral suspension was centrifuged (9,820×g for 30 min at4° C.) and the viral pellet re-suspended in 10 ml PBS. A Vertrel XFextraction was performed at a 1:1 ratio to promote monodispersion of thevirus and the removal of lipids (centrifugation at 7,500×g for 15 min at4° C.) (Black et al., 2009). The top aqueous layer containing the viruswas carefully removed using a pipette and aliquoted in 1 ml volumes insterile cryogenic vials (VWR, Radnor, Pa.). A viral titration forpoliovirus 1 was performed using a 10-fold serial dilutionplaque-forming assay described by Bidawid et al., “A feline kidney cellline-based plaque assay for feline calicivirus, a surrogate for Norwalkvirus.” J. Virol. Methods 107: 163-167. (2003). BGM cell monolayers in6-well tissue culture plates (Corning Inc., Corning, N.Y.) were rinsedtwice with TRIS buffered saline[0.32 L TBS-1 (31.6 g/L Trizma base, 81.8g/L NaCl, 3.73 g/L KCl, 0.57 g/L Na₂HPO₄— anhydrous) in 3.68 L ultrapureH₂O] and then inoculated with 0.1 ml volumes of 10-fold serial dilutionsof the virus stock and incubated at 37° C. for 30 minutes. Followingthis incubation period, 3 ml of a molten solution of MEM containing (per100 ml) 0.75% Bacto-agar (Becton, Dickenson and Co., Sparks, Md.), 2%FBS (HyClone Laboratories, Logan, Utah), 3 ml of 1 M HEPES buffer(Mediatech Inc., Manassas, Va.), 1 ml of 7.5% sodium bicarbonate (FisherScientific, Fair Lawn, N.J.), 1 ml of 10 mg/ml kanamycin (HyCloneLaboratories, Logan, Utah), 1 ml of 100× antibiotic-antimycotic (HyCloneLaboratories, Logan, Utah), and 1 ml of 200 mM glutamine (Glutamax;HyClone Laboratories, Logan, Utah) was added as an overlay to each welland allowed to solidify. The plates were then incubated at 37° C. with5% CO₂ for two days. Following incubation, the agar overlays wereremoved and the cell monolayers were stained with 0.5% (w/v) crystalviolet (Sigma-Aldrich, St. Louis, Mo.) dissolved in ultrapure water andmixed 1:1 with 95% ethanol. Plaques were counted to enumerate infectiousviruses.

Maintenance and Preparation of Mold Isolates:

Test molds were obtained from the American Type Culture Collection(ATCC, Manassas, Va.) or The University of Arizona, Tucson, Ariz.:Trichophyton mentagrophytes (ATCC #9533), Streptoverticilium reticulum(ATCC #25607). Penicillium and Aspergillus niger isolates were obtainedfrom Dr. Charles Gerba at the University of Arizona.

T. mentagrophytes, Penicillium and Aspergillus niger isolates weremaintained on Sabouraud's agar (Neogen Corporation, Lansing, Mich.)slants at 25° C. S. reticulum isolates were maintained on Yeast MaltExtract Agar (ISP Medium 2) containing (per 1 liter deionized water),4.0 g yeast extract(Beckton Dickinson, Franklin Lakes, N.J.), 10.0 gmalt extract(Amresco, Solon, Ohio), 4.0 g dextrose (Hardy Diagnostics,Santa Maria, Calif.), and 20.0 g agar (EMD Chemicals, Gibbstown, N.J.).For preparation of Penicillium and Aspergillus niger spore suspensions,mature slant cultures containing fruiting bodies were washed repeatedlywith 10 mL of sterile PBS to release spores. The spore suspension wasthen transferred to a 15 mL conical tube and vortexed to disperse thespores. For preparation of T. mentagrophytes spore suspensions, methodswere adapted from the ASTM 2111-05 standard (ASTM Standard 2111, 2005,“Standard Quantitative Carrier Test Method to Evaluate the Bactericidal,Fungicidal, Mycobactericidal, and Sporicidal Potencies of LiquidChemical Microbicides.” ASTM International, West Conshohocken, Pa.,2005.). A small section of mycelial mat from mature slant cultures wastransferred to 3-4 plates of Sabouraud's agar. These were incubated for10-15 days at 25° C. Mature mycelial mats were removed from the agarsurface and placed into a 250 ml Erlenmeyer flask containing 50 mlsterile saline (0.85% NaCl) and glass beads. The flask was shakenvigorously to release conidia spores from the fungal hyphae and thesuspension was filtered through sterile cotton to remove hyphaefragments.

1) Liquid Suspension Testing

Bacterial Reduction Assay.

Overnight suspensions were harvested by centrifugation (9,820×g, 15 min,20° C., JA-14 rotor, Beckman J2-21 centrifuge; Beckman Coulter, Inc.,Fullerton, Calif.) and resuspended in 100 ml of sterile PBS. The abovecentrifugation process was carried out two additional times to wash thecells and the final harvest was resuspended in 10 ml of PBS. Bacterialsuspensions were then adjusted in PBS to an optical turbidity (measuredusing a BIOLOG turbidimeter, Hayward, Calif.) equivalent to a McFarlandnumber 0.5 standard. Sterile 50 ml polypropylene conical tubes (BectonDickinson and Company, Franklin Lakes, N.J.) containing PBS wereinoculated with test suspensions to a final concentration ofapproximately 1.0×10⁶ CFU/ml. Functionalized particles of the presentinvention were evaluated at either 10 ppm silver or 60 ppm copper. Testsamples were then placed on an orbital shaker (300 rpm) at 25° C. forthe duration of the experiment. At predetermined time intervals (e.g.,1, 3, 5, 24 hours), 100 μl samples were collected and neutralized withDey Engley neutralizing broth (D/E; Difco, Sparks, Md.) at a ratio of1:10. Bacterial samples were serially diluted in sterile PBS andenumerated using the spread plate method (Eaton et al., “Spread PlateMethod,” in Standard Methods for the Examination of Water & Wastewater,21^(st) ed., American Public Health Association, Washington, D.C., pp.9-38-9-40. 9215C. 2005) with incubation at 37° C. for either 24 hours(E. coli, P. aeruginosa, S. aureus, S. Typhimurium and E. faecalis) or48 and 72 hours (M. fortuitum and S. mutans).

Evaluation of Antimicrobial Properties of Porous Silica Particles:

Experiments for porous silica particles without antimicrobial salt andthose comprising antimicrobial salt were conducted in 100 ml of sterilePBS in 250 ml Erlenmeyer flasks. Bacterial suspensions were added to afinal concentration of 1.0×10⁶ CFU/ml. Powdered silica samples weretested at 0.1 g dry weight per 100 ml of PBS. A control with bacteriabut no added particles was also included. Powdered silica samples wereadded to each flask and kept in suspension by agitation using stirplates (VWR VMS-C7, VWR, Radnor, Pa.) for the duration of the experimentat 25° C. At predetermined time intervals (e.g. 0.25, 1, 6, 24 hours), 1ml samples were collected and neutralized with D/E neutralizing broth ata ratio of 1:2. Samples were then diluted and enumerated as describedbefore.

Viral Reduction Assay.

Poliovirus 1 experiments were conducted in 10 ml of sterile PBS in 50 mlsterile polypropylene conical tubes (Becton Dickinson and Company,Franklin Lakes, N.J.). MS2 experiments were conducted in 50 ml ofsterile PBS in 250 ml sterile covered Pyrex beakers. The purified stocksof the viruses were added separately to the tubes/beakers to achieve thedesired final test concentration of approximately 1.0×10⁶ PFU/ml.Functionalized particles of the present invention were evaluated ateither 10 ppm silver or 60 ppm copper. The tubes/beakers were thenplaced on an orbital shaker (300 rpm) for the duration of theexperiment. Experiments were performed at 25° C. At predetermined timeintervals (e.g., 3, 5, 7, 24 hours), 100 μl samples were collected andneutralized with D/E neutralizing broth at a ratio of 1:10.Functionalized particle efficacy was determined by the agar overlaymethod as described above in maintenance and preparation of virusessection.

Mold Reduction Assay.

Sterile 50 ml polypropylene conical tubes (Becton Dickinson and Company,Franklin Lakes, N.J.) containing 10 ml PBS were inoculated with moldspore suspensions of approximately 1.0×10⁶ CFU/ml. Functionalizedparticles of the present invention were evaluated at either 10 ppmsilver or 60 ppm copper. Test samples were then placed on an orbitalshaker (300 rpm) at 25° C. for the duration of the experiment. Atpredetermined time intervals (e.g., 1, 3, 5, 24, 48, 72 and 96 hours),100 μl samples were collected and neutralized with D/E neutralizingbroth at a ratio of 1:10. Mold samples were serially diluted in sterilePBS and enumerated with the spread plate method (Eaton et al., “SpreadPlate Method,” in Standard Methods for the Examination of Water &Wastewater, 21^(st) ed., American Public Health Association, Washington,D.C., pp. 9-38-9-40. 9215C, 2005) with incubation at 25° C. for 48 and72 hours.

Determination of Antimicrobial Activity by Optical Density Measurements.

Bacterial suspensions with or without antimicrobial particles wheremonitored for growth using a turbidimetric measurement. Turbid or cloudysuspensions indicated growth or increase in biomass whereas clearsuspensions indicate no growth or no increase in biomass. A deficiencyor lack of growth correlates to the effectiveness of the antimicrobialparticles. Optical densities where monitored using a spectrophotometersuch as an Eppendorf Bio Photometer cuvette reader (Eppendorf NorthAmerica, Inc, Enfield, Conn.) or Biotek Synergy 2 multiwell plate reader(Biotek Inc., Winooski, Vt.).

Determination of Antimicrobial Activity Against Bacterial SporeGermination.

To determine antimicrobial activity against bacterial spores, sterile 2mL polypropylene tubes were inoculated with B. cereus spore suspensionsand treated with approximately 2 pM or 60 ppm of nanoparticles for 24hours at room temperature (22° C.). After 24 hours of incubation,suspensions were pelleted by centrifugation at 13,000×g, and thesupernatant removed and discarded. Pellets were resuspended in 200 μl ofTSB. The tubes were then incubated for 24 hours at 25° C. and 37° C.Germination characteristics of B. cereus spores after 24 hours ofincubation with nanoparticle chemistries were determined by opticaldensity (Eppendorf Bio Photometer) at a wavelength of 600 nm (OD600).

2) Coated Surface Testing

Experiments for coated stainless steel or aluminum surfaces with andwithout functionalized particles were conducted based on the JapaneseIndustrial Standard Z 2801:2000 method (JIS Z 2801:2000, “Antimicrobialproducts—Tests for antimicrobial activity and efficacy”, JapaneseStandards Association, Tokyo, Japan, 2000.) with minor modifications.Prior to the experiment, 50×50 mm square coupons of steel or aluminumwith the desired coating were disinfected with 70% ethanol twice and airdried. Overnight cultures of bacteria were washed and standardized asmentioned previously. Bacterial suspensions with a final concentrationof 1.0×10⁷ cfu/ml were prepared in PBS and 0.4 ml was inoculated ontoeach test surface. The inoculum was held in contact with the surfaceusing UV sterilized 40×40 mm polyethylene film cover slips. A set ofcontrol surfaces coated with polymer but containing no functionalizedparticles was also inoculated for a zero hour time point to determinethe initial inoculum concentration and at each time interval followingto determine the change in organism concentration without antimicrobial.All inoculated surfaces were incubated in a sealed environment at 25° C.and >95% relative humidity (RH). At predetermined time intervals (e.g.3, 6, 24 hours), the cover slip was aseptically removed and the bacteriawere recovered by swabbing the surface and the cover slip with a cottonswab pre-moistened in sterile PBS. The swab was then neutralized in 1 mlof D/E neutralizing broth and the cotton tip of the swab was broken offinto the tube containing D/E. Samples were then vortexed for 30 secondsand diluted/enumerated as described previously. Three replicate samplesfor each surface treatment were tested for each time interval in thismanner. Bacterial reductions were determined by comparing the recoveryof bacteria from the untreated control samples (polymer coated couponswithout functionalized particles) to those recovered from treatedsamples containing functionalized particles at each exposure interval.

A revised version of the JIS method was later developed to enable morerapid testing of polymer coatings. The method above was performed withsmaller surfaces (25×25 mm square coupons) and smaller polyethylenecoverslips (20×20 mm). Surfaces were disinfected with a slightlydifferent method to better preserve coating integrity; each surface wasdisinfected once with 70% ethanol and immediately irrigated with steriledeionized (DI) water before air-drying prior to the experiment. Surfaceswere inoculated with 0.1 ml of a of 1.0×10⁷ cfu/ml bacterial suspensionand were incubated as previously described. At predetermined timeintervals (e.g. 3, 6, 24 hours), samples were neutralized by completelysubmersing both the surface and the cover slip in 10 ml of D/Eneutralizing broth in sterile polypropylene bottles. These bottles weresealed and sonicated (30 seconds, nominal main frequency 67 KHz,Cavitator® Ultrasonic Cleaner, Mettler Electronics, Anaheim, Calif.) torecover bacteria from the surface and cover slip. The D/E solution wasdiluted/enumerated as described before. Three replicate samples for eachsurface treatment were tested for each time interval in this manner.Bacterial reductions were determined as described previously.

Certain coatings were tested under more rigorous experimental conditionsset forth in the EPA “Test Method for Efficacy of Copper Alloy Surfacesas a Sanitizer” with some modifications. Cultures of Staphylococcusaureus ATCC 25923 were grown for 48±4 hours. To simulate organic soilload, fetal bovine serum (FBS) and Triton X-100 were added to an aliquotof the overnight culture for a final concentration of 5% FBS and 0.01%Triton X-100. Test surfaces with the desired coating (25×25 mm squarecoupons) were disinfected as described for the revised JIS method above.Each test surface was inoculated with 20 μl of the culture with organicload and spread uniformly on the surface with a sterile glass rod andallowed to dry completely (approx. 20 min at 22° C., 20-45% RH). Nocover slip was used for this experiment. A set of control surfacescoated with polymer but containing no functionalized particles was alsoinoculated for a zero hour time point to determine the initial inoculumconcentration after drying and at the 120 minute time interval todetermine the change in organism concentration without antimicrobial. Atthe end of the drying period, samples were incubated at room temperature(22° C., 20-45% RH) in sterile covered petri dishes for 120 minutes.Samples were then neutralized in D/E and sonicated for 30 as describedpreviously. The D/E solution was diluted/enumerated as described before.Three replicate samples for each surface treatment were tested for eachtime interval in this manner. Bacterial reductions were determined asdescribed previously.

3) Spray Antimicrobial Testing

The following procedure was used to determine the efficacy offunctionalized particles used in spray applications. Test carriers(glazed 4.25″×4.25″ ceramic tiles) were washed, treated with 10% bleach,and rinsed before being sprayed with 70% ethanol and allowed to air dry.Spray bottles were checked prior to testing to determine that eachbottle dispensed similar volumes of liquid when sprayed. The bottles andspray nozzles were thoroughly washed and rinsed with DI water followedby 70% ethanol. The ethanol was allowed to dry and each bottle/nozzlewas rinsed with sterile DI water. The bottles were emptied and the testsamples were added aseptically to each bottle. In addition to testsprays, a solution of phosphate buffered saline (PBS) was used as acontrol (non-antimicrobial) spray. An overnight culture of the bacteriaof interest was prepared in 100 ml of tryptic soy broth and centrifugedand washed in PBS as previously described. After the finalcentrifugation step, the bacterial pellet was re-suspended in 1/10 ofthe original volume (10 ml) in PBS. From this solution, 0.1 ml wasinoculated onto each test carrier and spread uniformly across thesurface with a sterile glass rod. Each carrier was allowed to drycompletely before spray testing (approx. 20 min at 22° C., 20-45% RH).Each carrier was sprayed uniformly (fine mist setting) with the testsolutions just to the point of covering the surface (approx. 2.5 ml). Aset of samples sprayed with PBS were sampled immediately after sprayingas a zero hour to serve as a control sample to determine the initialinoculum concentration on each carrier. The remaining surfaces wereincubated at room temperature (22° C., 20-45% RH) in open air. Atpredetermined time intervals (e.g. 0.25, 1, 6 hours), bacteria wererecovered by swabbing the surface with a cotton swab pre-moistened insterile D/E neutralizing broth. The swab was then neutralized in 1 ml ofD/E and the cotton tip of the swab was broken off into the tubecontaining D/E. Samples were then vortexed for 30 seconds. In somecases, where the spray samples were more acidic and thus were notcompletely neutralized at a 1:10 dilution, the sample was immediatelydiluted following the vortex step in 1:100 in PBS. In both cases, theneutralized sample was diluted/enumerated as described before. Threereplicate samples for each spray treatment (including the PBS controlsolution) were tested for each time interval in this manner. Bacterialreductions were determined by comparing the recovery of bacteria fromthe control carriers (those sprayed with PBS solution) to thoserecovered from carriers sprayed with test samples containingfunctionalized particles at each exposure interval.

The following procedure was used to determine if sprays containingfunctionalize particles could impart some residual antimicrobial effecton sprayed surfaces. Test carriers and spray bottles were prepared aspreviously described for spray testing. Spray bottles were filled withtest samples and phosphate buffered saline (PBS) was used as a controlspray. An overnight culture of bacteria was prepared as previouslymentioned for spray testing but was not immediately applied. Each testcarrier was sprayed uniformly with the test solutions just to the pointof covering the surface (approx. 2.5 ml). A set of samples sprayed withPBS was also included for each time interval. Each spray sample wasallowed to sit undisturbed on the surface for a two minute conditioningtime after which the surface was wiped with a paper towel to removeexcess liquid. The surfaces were held at room temperature (22° C.,20-45% RH) for a predetermined “residual time” (e.g. 0, 3, 24 hours).Following this, 0.1 ml of the bacterial concentrate were inoculated ontoeach test carrier and spread uniformly across the surface with a sterileglass rod. The surfaces were incubated at room temperature (22° C.,20-45% RH) in open air. Immediately after inoculation and atpredetermined “post-inoculation” time intervals (e.g. 1, 3, 6 hours),the bacteria were recovered by swabbing and neutralized as describedpreviously for spray testing. The neutralized sample wasdiluted/enumerated as described previously. Three replicate samples foreach spray treatment (including the PBS control solution) were testedfor each time interval in this manner. Bacterial reductions weredetermined as described previously for spray testing.

4) Cream/Shampoo Antimicrobial Testing

Experiments for cream, lotion, and shampoo based samples with andwithout functionalized particles were conducted based on the USP <51>method (“Antimicrobial Effectiveness Testing.”, U.S. Pharmacopeia,Rockville, Md.) with minor modifications. Briefly, overnight cultures ofbacteria were centrifuged, washed and standardized in PBS as detailed inprevious sections. The bacterial suspension was diluted as needed for aspecific experiment, ranging from 1×10⁷-1×10⁹ cfu/ml. For each sample, 1g aliquots were placed into sterile polystyrene tubes. In addition, 1 mlaliquots of PBS were used as a control solution. Each aliquot wasinoculated with 0.01 ml of the washed bacterial suspension containing 10times the desired final test concentration and mixed with a sterilewooden applicator or lightly vortexed depending on the viscosity of thesample. At predetermined time intervals (e.g. 7, 14, 28 days), sampleswere taken by adding 1 ml D/E neutralizing broth to the sample andvortexing lightly to mix. Samples were then diluted/enumerated andbacterial reductions were determined as described previously. Allsamples were tested in duplicate.

A zone of inhibition type assay was also used to determine the efficacyof functionalized particles in cream and petroleum gel products.Overnight cultures of bacteria were centrifuged, washed and standardizedin PBS as described previously. The standardized bacterial solution wasdiluted to a concentration of 1×10⁴ cfu/ml. Plates of tryptic soy agar(TSA) were inoculated with 0.1 ml of the diluted bacteria. A sterileagar punch (approx. 5 mm in diameter) was used to remove a plug of agarfrom each inoculated plate, creating a well in the center of the plate.Samples of cream or petroleum gel with and without functionalizedparticles were added until the entire well was filled with sample(approx. 0.05 ml). A plate with agar plug removed but without addedsample was also included as a positive growth control sample. All plateswere covered and incubated at 37° C. for 24 hours. The diameter of theresulting zone of inhibition (area with no bacterial growth or inhibitedbacterial growth) was measured for each sample and compared with boththe positive growth control and samples without funtionalized particlesto determine their relative antimicrobial efficacy.

5) Streptoverticilium reticulum Polymer Staining Test

Anti-staining experiments for polymer foams containing functionalizedparticles were conducted based on ASTM E1428-99 standard method (ASTME1428-99, “Standard Test Method for Evaluating the Performance ofAntimicrobials in or on Polymeric Solids Against Staining byStreptoverticilium reticulum (A Pink Stain Organism)”, ASTM, WestConshohocken, Pa., 2009). Briefly, samples of polymer foam were cut topredefined dimensions (e.g., 10 mm, 30 mm square coupons). Plates ofyeast malt extract agar (ISP Medium 2, see above in Maintenance andpreparation of mold isolates) were poured to a depth of 5 to 8 mm andallowed to solidify before testing. A stock plate of S. reticulum wasgrown prior to experimentation for 7-14 days. In order to harvest S.reticulum cells, 3 ml of sterile PBS were added to the stock plate and asterile cotton swab was used to break up the fungal mat. This swab wasused to streak fungal cells onto plates of ISP Medium 2. A coupon of thesample foam was applied to the center of the inoculated plate andpressed lightly to ensure good contact between the agar surface and thesample. In addition, a foam sample containing no functionalizedparticles was also tested. Samples with and without functionalizedparticles were also applied to ISP Medium 2 without the presence ofinoculum to determine if staining occurred in foam samples as a resultof the agar alone. Three replicate samples were tested for eachtreatment. All plates were covered and incubated at 30° C. under humidconditions (approx. 95% RH) for 14 days. All plates were observed forzones of inhibition present in the newly grown fungal mat. Samples werethen removed from the agar surface to observe for staining Samples wererated on a scale from 1 to 5 with a value of ‘1’ pertaining to the colorof fresh, untested foam samples and a value of ‘5’ pertaining to themaximum amount of stain observed on foam samples containing noantimicrobial exposed to S. reticulum. Samples exposed to agar withoutinoculum were also scored against this scale.

6) Wound Dressing Antimicrobial Testing

The following procedure was used to determine the antimicrobial efficacyof wound dressings containing functionalized particles. Wound dressingswere provided as sterile 10 mm diameter disks. An overnight culture ofP. aeruginosa (ATCC #9027) was prepared as previously described but wasnot centrifuged or washed. Polycarbonate membrane films (25 mm diameter,0.2 μm pore size, Whatman) were sterilized by autoclaving and placed inthe center of TSA plates. The overnight culture was diluted 1:10,000 inPBS and 0.01 ml was inoculated as a single spot in the center of eachmembrane filter. These plates were incubated at 37° C. for 24 hours toallow for the formation of bacterial biofilms. After growth, eachmembrane filter was transferred to a fresh TSA plate. Wound dressingsamples were moistened with 0.05-0.2 ml DI water and applied gently tothe biofilm spot. The biofilms with wound dressings were incubated at37° C. for 18 hours. Each wound dressing and membrane filter weretransferred to 10 ml of D/E neutralizing broth, vortexed for 1 min andsonicated for 1 minute (described previously) to release bacteria fromthe surfaces. The neutralized samples were diluted/enumerated asdescribed previously. Bacterial reductions were calculated and comparedwith the control samples containing no functionalized particles andbiofilm control samples with no applied wound dressings.

7) Pet Chew Antimicrobial Testing

The following procedure was used to evaluate the antimicrobial efficacyof pet chews treated with functionalized particles. Treated anduntreated pet chews (pig ears) were cut to 1″×0.5″ pieces and placedinto empty sterile petri dishes. All pet chews were incubated in sealedcontainers at room temperature (22° C., >95% RH) in order to reduceliquid absorption by the pet chews. Overnight cultures of bacteria werecentrifuged and washed as described previously. A 1×10¹⁰ cfu/ml solutionof bacteria was prepared and 0.1 ml was inoculated onto each pet chew. Asterile glass spreading rod was used to spread the inoculum to cover thetop surface of the pet chew. A set of untreated pet chews containing nofunctionalized particles was also inoculated for a zero hour time pointto determine the initial inoculum concentration and for each timeinterval following to determine the change in organism concentrationwithout antimicrobial. All samples were incubated in sealed containersat 22° C. and >95% RH. At predetermined time intervals (e.g. 1, 6, 24hours), samples were neutralized by submerging the entire pet chew in 10ml D/E neutralizing broth, vortexed for 30 seconds and sonicated(described previously) for 1 minute to release bacteria from thesurfaces. The D/E solution was diluted/enumerated as describedpreviously. Bacterial reductions were calculated and compared withuntreated control samples containing no functionalized particles.

Preparation of Materials and Results Example 1 Synthesis of CuIParticles Functionalized with PVP at Cu/PVP=1/3.3 w/w

10% PVP solution was made by dissolving 1 g Polyvinylpyrrolidone, mol.wt.=10,000 (Sigma-Aldrich #PVP10) in 9 g water. 2.232 g of this solutionwas added into the solution of 0.211 g Copper(II) acetate monohydrate(Sigma-Aldrich #217557) solution prepared by dissolving 1.057 mmol ofthe monohydrate in 6.227 g water under stirring. Afterwards, 0.3168 gsodium iodide (2.114 mmol) dissolved in 5 g water was dropped slowlyinto the copper solution and stirred overnight. Next day, the CuIsuspension was washed to remove the formed iodine by extracting 7-10times 2.5-3 ml with diethyl ether. The remaining ether was separatedfrom the solution by evaporation under vacuum and then water was addedto compensate for the loss of weight during processing. The finalconcentration of copper based on the calculation of metallic copper is0.48% w/w. Reaction: Cu²⁺+2I⁻→CuI₂→CuI_((s))+I₂. 10% Aspartic acidsolution was made using 0.296 g NaOH pellets (7.4 mmol) which wasdissolved in 8.6 g water, 0.988 g Aspartic acid (7.4 mmol) (Sigma#A9006) added into the sodium hydroxide solution and then stirred untila clear solution was obtained. The aspartic acid solution was added tothe CuI solution in a proportion so that the ratio of PVP/Aspartic acid(molar) was 1:2.5.

This solution was tested against Poliovirus (PV-1 LSc-2ab). The testingwas carried out on Poliovirus (at 60 ppm copper concentration).Functionalized CuI particles were found to be particularly effectiveagainst poliovirus, with decreases in microbial populations 3.11 log₁₀reduction being found in 24 hours. A further encouraging result of thetesting on poliovirus was the observation of the cell culture workcarried out here, which showed no adverse effect of the functionalizedparticles on cell viability and reproduction in culture.

Example 2 Synthesis of CuI-PEG Dispersion w/pH Modifier

A dispersion of CuI surface modified with polyethylene glycol (PEG) wasprepared in water using nitric acid as a pH modifier. To a reactionflask fitted with a stir bar was added 4.5 g of PEG (MW=10,000), and0.0476 g CuI (99.999%) and 50 ml of acetonitrile. The mixture wasstirred at room temperature for about 30 minutes to give a light greensolution. The reaction flask was placed on a rotary evaporator and thesolvent removed at 25° C. to a paste-like consistency. The temperaturewas then increased to 45° C. to complete removal of acetonitrile. Thisresulted in a yellow powder. This powder was dispersed in 50 ml of DIwater and 0.05 ml (0.07 g) of concentrated nitric acid was added to forman off-white mixture. Upon stirring in the dark over night thedispersion became clear to give a light yellow dispersion.

Example 3 Preparation of Ag/PVP Dispersion

To a round bottom flask fitted with a condenser was added 50 ml of DIwater (18 Mohm-cm) and 20 g of PVP (10,000 MW, Sigma Aldrich Cat.#PVP10). The mixture was stirred at room temperature to form a clearyellow solution. To this solution was added 0.04926 g of silver nitrate(≧99.0% ACS reagent Sigma Aldrich Cat. #209139) and the solution heatedto 70° C. for 7 hours while stirring. During this time the reaction wasfollowed by optical absorption with the formation of the Plasmon peak at425 nm due to the reduction of silver nitrate to silver metal by PVP.The final dispersion of Ag nano-particles was orange/brown in color andwas transparent. Dynamic light scattering on a dilute sample of thedispersion gave a mean particle size of 7 nm.

Example 4 Synthesis of AgBr/PVP Dispersion

A silver bromide dispersion was prepared by dissolving 20 g of PVP(10,000 MW, Sigma Aldrich Cat. #PVP10) in 40 ml of DI water (18Mohm-cm). To this solution while stirring was added 0.0492 g of silvernitrate, (≧99.0% ACS reagent Sigma Aldrich Cat. #209139), resulting in aclear yellow solution. In a separate reaction vessel a reducing solutionwas prepared by dissolving 0.0357 g of potassium bromide (anhydrouspowder 99.95% Sigma Aldrich Cat. #451010), in 10 ml DI water (18Mohm-cm). This KBr solution was added drop wise to the AgNO₃/PVPsolution to form a yellow/orange transparent dispersion of AgBr. Dynamiclight scattering on a dilute sample of the dispersion gave a meanparticle size of 4 nm.

Example 5 Synthesis of CuI/PVP Dispersion

To a reaction flask containing 50 ml of anhydrous acetonitrile, (99.8%Sigma Aldrich Cat. #271004), was added 10 g of PVP (10,000 MW, SigmaAldrich Cat. # PVP10) and stirred to form a light yellow solution. Tothis solution was added 0.0476 g of CuI (98.0% Sigma Aldrich Cat.#205540) and after stirring for 30 minutes this resulted in a clear palegreen solution. Then the bulk of the acetonitrile was removed underreduced pressure at 30° C. to form a viscous paste. The temperature wasthen increased to 60° C. to completely remove the solvent to give a palegreen solid. To this solid was added 50 ml of DI water (18 Mohm-cm) andstirred to form a transparent bright yellow dispersion. Dynamic lightscattering on a dilute sample of the dispersion gave a mean particlesize of 4 nm.

Example 6 Synthesis of PVP-BASF-CuCl Dispersion

To a reaction flask containing 50 ml of anhydrous acetonitrile (99.8%Sigma Aldrich Cat. #271004) was added 14 g of PVP (BASF K17) and stirredto form a clear solution. To this solution was added 0.0239 g of CuCl(ACS reagent >99.0% Sigma Aldrich Cat. #307483) and after stirring for30 minutes this resulted in a green/yellow solution. The bulk of theacetonitrile was removed under reduced pressure at 30° C. to form aviscous paste. The temperature was increased to 60° C. to completelyremove the solvent to give a pale green solid. To this solid was added50 ml of DI water (18 Mohm-cm) and stirred to give a transparent brightyellow dispersion.

Example 7 Synthesis of CuI/PVP-BASF+Acetic Acid+HNO₃

To a reaction vessel were added 4.05 g of PVP (BASF K17) and 50 ml ofanhydrous acetonitrile (99.8% Sigma Aldrich Cat. #271004). This wascapped and left to stir at room temperature to form a clear colorlesssolution. To this solution was added 0.0476 g of CuI (99.999% SigmaAldrich Cat. #215554) and stirred at 25° C. for 30 minutes to form atransparent light yellow solution. The bulk of the acetonitrile wasremoved under reduced pressure at 30° C. to form a viscous paste. Thetemperature was increased to 60° C. to completely remove the solvent togive a yellow uniform solid. To this solid was added 50 ml of DI water(18 Mohm-cm) and stirred to give a cloudy white dispersion. This wasleft to stir for 3 days in the dark the dispersion remained cloudy witha light white precipitate. While stirring 0.3 ml of glacial acetic acid(ACS reagent ≧99.7% Sigma Aldrich Cat. #320099) was added andimmediately the dispersion turned a orange/yellow color but was cloudywith a slight precipitate. To this mixture was added 0.05 ml ofconcentrated nitric acid (ACS reagent ≧90% Sigma Aldrich Cat. #258121)and the solution cleared up to give a transparent light yellow solution.

Example 8 Synthesis of CuI/VP-VA Copolymer-BASF+HNO₃ dispersion

To a reaction flask containing 50 ml of anhydrous acetonitrile (99.8%Sigma Aldrich Cat. #271004) was added 6.75 g of the copolymer PV-VA(BASF Luvitec VA 64) and stirred to form a clear solution. To thissolution was added 0.0476 g of CuI (99.999% Sigma Aldrich Cat. #215554)and after stirring for 30 minutes this resulted in a green/yellowsolution. The bulk of the acetonitrile was removed under reducedpressure at 30° C. to form a viscous paste. The temperature was thenincreased to 60° C. to completely remove the solvent to give a yellowuniform solid. To this solid was added 50 ml of DI water (18 Mohm-cm)and stirred to give a cloudy light yellow slurry. Under stirring 0.05 gof concentrated nitric acid (ACS reagent ≧90% Sigma Aldrich Cat.#258121) was added to the mixture and it turned a light yellow color andwas transparent.

Example 9 Synthesis of CuI/PVP-BASF+HNO₃

To a round bottom flask fitted with a stir bar were added 4.275 g of PVP(BASF K17) and 50 ml of anhydrous acetonitrile (99.8% Sigma Aldrich Cat.#271004). This was capped and left to stir at room temperature to form aclear colorless solution. To this solution was added 0.225 g of CuI(99.999% Sigma Aldrich Cat. #215554) and stirred at 25° C. for 30minutes to form a transparent light yellow solution. The bulk of theacetonitrile was removed under reduced pressure at 30° C. to form aviscous paste. The temperature was then increased to 60° C. tocompletely remove the solvent to give a yellow uniform solid. To thissolid was added 50 ml of DI water (18 Mohm-cm) and stirred to give acloudy light yellow dispersion. While stirring 0.07 g of concentratednitric acid (ACS reagent ≧90% Sigma Aldrich Cat. #258121) was added tothe mixture and it turned colorless and lightly cloudy with noprecipitate. Dynamic light scattering on a diluted sample of thedispersion showed a bimodal distribution for volume fraction analysiswith particles with peaks at diameter of 263 and 471 nm.

In another preparation following the above route, the proportion ofcomponents was changed. The amount of PVP (BASF K17) was 2.25 g in 50 mlacetonitrile. To this was added 0.0476 g of CuI (99.999%). This wasprocessed as before and the dry powder was redispersed in 60 ml DIwater. The solution was milky/pale yellow. After stirring 0.05 ml ofnitric acid was added and stirred for two days. The solution becameclear yellow with no precipitate. The solution remains stable after thisprocess. The particle size was 4 nm.

Example 10 Synthesis of Ag_(0.5)Cu_(0.5)I and Ag_(x)Cu_(1-x)BrNanoparticles

This method results in “solid solutions,” meaning not separate distinctliquid phases of CuI and AgI but where one metal is substituted for theother randomly throughout the crystal or a non-crystalline latticestructure of the solid. For example, Ag_(0.5)Cu_(0.5)I may be considereda solid solution of CuI and AgI where both are present in equimolarquantities, or one may consider CuI is about 51% by weight and AgI is49% by weight. 10 g of PVP (10,000 MW, Sigma Aldrich Cat. #PVP10) wasdissolved in 40 ml of DI water (18 Mohm-cm) and to this was added 0.0246g (0.145 mmol) of silver nitrate (≧99.0% ACS reagent Sigma Aldrich Cat.#209139). To this pale yellow solution was added 0.0350 g (0.145 mmol)of copper nitrate trihydrate, (≧98% Sigma Aldrich Cat. #61197), to givea dark yellow solution. In a separate vessel 0.0481 g (0.29 mmol) ofpotassium iodide, (≧99.0% ACS reagent Sigma Aldrich Cat. #60400), wasdissolved in 10 ml DI water (18 Mohm-cm) and added drop wise (0.34ml/minute) to the silver, copper nitrate PVP solution. This resulted ina pale yellow dispersion of a solid solution of silver-copper iodide(Ag_(0.5)Cu_(0.5)I). Dynamic light scattering on a dilute sample of thedispersion gave a mean particle size of 29 nm.

Silver-copper-bromide nanoparticles were synthesized following the sameprocedure as for silver-copper-iodide using KBr instead of KI.Silver-copper-iodide-bromide nanoparticles were prepared in the samefashion using a combination of KI and KBr in a (1−y):(y) mole ratio.

Example 11 Synthesis of Ag_(0.25)Cu_(0.75)I Nanoparticles

Nano-particle dispersion of silver copper iodide solid was preparedaccording to Example #10 except that the molar concentrations of themetal ions were adjusted according to the formula Ag_(0.25)Cu_(0.75)I.Dynamic light scattering of a dilute sample of the dispersion gave amean particle size of 10 nm. In this example, Ag_(0.25)Cu_(0.75)I may beconsidered a solid solution of CuI and AgI where both are present inmolar ratio of 25% AgI and 75% CuI, or one may consider CuI is about 71%by weight and AgI is 29% by weight.

Example 12 Synthesis of Ag_(0.75)Cu_(0.25)I Nanoparticles andAntimicrobial Activity of Ag_(x)Cu_(1-x)I

Nano-particle dispersion of silver copper iodide solid was preparedaccording to Example 10 except that the molar concentrations of themetal ions were adjusted according to the formula Ag_(0.75)Cu_(0.25)1.Dynamic light scattering of a dilute sample of the dispersion gave amean particle size of 8 nm. In this example, Ag_(0.75)Cu_(0.25)I may beconsidered a solid solution of CuI and AgI where both are present inmolar ratio of 75% AgI and 25% CuI, or one may consider CuI is about 21%by weight and AgI is 79% by weight.

Antimicrobial testing of Ag—Cu mixed metal halides (made in Examples 10,11 and this one, i.e., Example 12) and their performance comparison withCuI was done using optical density method. FIG. 1 is a plot bar chart ofOptical Density (OD, Y-axis) as a measure of growth against the effectof copper iodide particles and Ag—CuI mixed metal halides, and acontrol. Optical density was measured after treating the bacterialsolutions with the nanoparticles of mixed metal halides (or solidsolutions of mixed metal halides). Lower optical density implies growthinhibition and showed higher effectiveness. Ag_(0.25)Cu_(0.75)I,Ag_(0.5)Cu_(0.5)I, and Ag_(0.75)Cu_(0.25)I all showed effectiveantimicrobial properties against P. aureginosa (FIG. 1) and S. aureus(FIG. 2), however, none were as effective as CuI nanoparticles alone(CuI was made as in Example 5 by using the acetonitrile process). Thedata shows that with increasing copper content in the solid solution theefficacy of the material increased.

Example 13 Infusion of Metal and Inorganic Metal Compounds into PorousParticles

The copper halide-porous particle composition is demonstrated by twoprocess embodiments which were used to infuse copper halide into poroussilica carrier particles. Various types of porous silica particles wereused from Silicycle Inc. (Quebec City, Canada). These were IMPAQ®angular silica gel B10007B hydrophilic silica. They had average particlesize of 10 μm and a pore size of 6 nm, with pore volume of about 0.8ml/g and a surface area of >450 m²/g); or silica with particle size of 0to 20 μm range (pore size 6 nm, surface area 500 m²/g); or silica 0.5 to3 μm in range (product number R10003B, pore size 6 nm).

Method 1

0.6 g of CuI (from Sigma Aldrich, 98.5% purity) was dissolved in 20 mlacetonitrile at room temperature (use of about 0.68 g of CuI would havesaturated the solution). 1 g of silica powder (0-20 μm) was added tothis solution. The solution was stirred for three hours at roomtemperature (this time period could have varied from a few seconds tomore than three hours), then filtered through 0.45 μm nylon filter (fromMicron Separations Inc., Westboro, Mass.) and finally dried at 70° C.The process may be repeated to increase the halide content. Using aspatula, the material is easily broken down into a fine powder. Theanalysis of this silica using inductively coupled plasma (ICP) atomicabsorption spectroscopy at a commercial laboratory showed that thecopper by weight was 1.88% of silica.

Example 14 Infusion of Metal and Inorganic Metal Compounds into PorousParticles

Method 2

In this method the solvent for CuI was 3.5 M KI solution in water. KIsolution was prepared by dissolving 29 g of KI in 40 ml of deionizedwater, stirring and adding water to complete a final volume of 50 ml.The volume of the KI solution after mixing was measured to be 50 ml.1.52 g of CuI was added and stirred at room temperature. The solutionturned yellow immediately and by the next day it darkened somewhat. To 6ml of this solution, 0.5 g of porous silica carrier particles (0.5 to 3μm) were added and stirred for six hours. The silica particles werefiltered and were then added to water so as to precipitate CuI trappedon the surface of the silica. The analysis of this silica using ICP AAinstrument showed that the copper by weight was 1.46% of silica.

Example 15 Preparation of Polyurethane/CuI Dispersions by Wet Grinding

The samples were ground in a wet grinding mill produced by NetzschPremier Technologies LLC (Exton Pa.), equipment model was Minicer®. Thegrinding beads were made of YTZ ceramic (300 μm in diameter). Theinterior of the mill was also ceramic lined. 99.9% purity CuI was usedto be ground to finer particle size using aqueous media. Two differenttypes of aqueous media were used. In the first case the material was analiphatic urethane 71/N aqueous dispersions (35% solids) sold under theTradename of ESACOTE® obtained from Lamberti SpA, (Gallarate, Italy).This material is used for aqueous furniture varnishes and also for metalcoatings. The second material was a PVP (Aldrich molecular weight10,000) solution in water.

For the polyurethane dispersion, 10 g of copper iodide was added forevery 100 ml of dispersion. As the grinding proceeded, the viscosityincreased and the dispersion was diluted with a mixture of 7% n-ethylpyrrolidone and 93% water by weight. 60 ml of diluents was addedthroughout the process. The samples started out with 50 grams CuI and500 grams of the PU dispersion. It should be noted that the surface ofthe ground particles was being functionalized by the PU dispersion(which comprised of hydrophobic polyurethane and a surfactant amongstother additives). A total of 60 grams of 7% 1-ethyl-2-pyrrolidone wasadded periodically throughout the milling process as follows: 25 gramsat 75 minutes, 10 grams at 105 minutes, 15 grams at 120 minutes, and 10grams at 150 minutes. Approximately 100 mL of product was taken out ofthe mill at 75 and 105 minutes (before the addition of the solvent), andthe remainder was pumped out at the 210 minute mark. At the end theprocess, the total solids content including CuI was 35%, the polymericcontent was 27.2% and the % of CuI to that of the polymer was 28.6%.During grinding the maximum temperature was 38° C. After 210 minutes ofgrinding, the particle size was measured. The circulation speed andagitation speed settings on the equipment were both at six. Particlesize measurement was conducted by HORIBA Laser Scattering Particle SizeDistribution Analyzer (model LA-950A). The average particle size was 68nm with a standard deviation of 7.4 nm. To test the stability of thesuspension with ground particles, the particle size was measured againthe next day which gave the mean size as 70 nm with a standard deviationof 8.2 nm.

Example 16 Preparation of PVP/CuI Dispersions by Wet Grinding

For the PVP dispersion, the formulation was 480 grams: 20 grams CuI, 60grams PVP (Aldrich 10,000 MW), 400 grams de-ionized water. Grindingparameters were the same as in Example 15. Samples were pulled out after45, 120 and 210 minutes of grinding under the same conditions as above(Example 15), the particle size (mean size) was respectively 920 nm(bimodal distribution with peaks at 170 and 1,500 nm), 220 nm and 120 nmrespectively, when measured using the HORIBA apparatus as describedabove.

Example 17 Effect of CuI Particles on Inhibiting the Growth of Spores

FIG. 3 is a bar chart that shows the effect of CuI/PVP inhibition on B.cereus spores growth. CuI/PVP suspensions were made as in Example 5, andthe copper concentration was 59 ppm in the final medium comprisingCuI/PVP and the bacterial broth. This figure clearly shows theeffectiveness of CuI/PVP in preventing B. cereus spores growth, and infact even achieving a slight reduction as compared to the starting sporeconcentration.

Examples 18-23 Additional Antimicrobial Results Using ParticulateSuspensions

Antimicrobial testing was carried out on the following microbes:

Ex. 18—Pseudomonas aeruginosa (ATCC 27313) (Table 5)

Ex. 19—Staphylococcus aureus (ATCC 25923) (Tables 6)

Ex. 20—Streptococcus mutans (ATCC 25175) (Table 7)

Ex. 21—S. enterica Typhimurium (ATCC 23564) (Table 8)

Ex. 22—Penicillium (Table 9)

Ex. 23—Aspergillus niger (Table 10)

Table 4 is a list of samples, particle sizes and functionalization usedin subsequent tables 5-10 with antimicrobial results. The particle sizein this table was measured using dynamic light scattering (here andabove, unless mentioned otherwise). In some cases the particle size wasconfirmed by optical absorption or by scanning electron microscopy(SEM). For measurement by dynamic light scattering, the particlesuspensions were diluted in DI water by taking one to two drops of thesuspension and adding several ml of water to ensure that a clear (to theeye) solution was obtained in a 1 cm path length cuvette. If theparticles were large, the solutions were stirred just beforemeasurement. Several measurements were made to ensure repeatability andreproducibility of samples. Most measurements were carried out using aMalvern Zetasizer Nano ZS light scattering analyzer (available fromMalvern Inc, Westborough, Mass.) at ambient temperature, with abackscatter mode at a 173° scattering angle or using DynaPro NanoStar byWyatt Technologies (Santa Barbara, Calif.), with a Laser Wavelength(nm)=661). Commercial polystyrene spheres with known size (60 nm) wereused for instrument calibration. Some of the measurements were also madeon the Nanotrac particle analyzer (available from Microtrac Inc,Montgomeryville, Pa.), also in the backscattering mode using afiberoptic probe. The data was converted and reported in the volumefraction mode.

TABLE 4 Preparation Metal or Sample method halide (CuI Surface Particlenumber (Example#) purity, %) Modification size*, nm S10 4 AgBrPVP-Aldrich 4 E S11 3 Ag PVP-Aldrich 7 E S12 5 CuI (98) PVP-Aldrich >15E S13 10 Ag_(0.5)Cu_(0.5)I PVP-Aldrich 29  S14 5 CuI (98)PVP-Aldrich >30 E S16 S17 5 CuI (98) PVP-Aldrich 4 E S18 4 AgBrPVP-Aldrich 4 E S19 4 AgBr PVP-Aldrich 4 E S26 5 CuI (98) PVP-Aldrich 4E S28 8 CuI(99.999) VP-VA 4 E Copolymer- BASF + HNO₃ S33 5 CuI (98)PVP-BASF 5 S34 2 CuI (99.999) PEG(10k, 4 E Aldrich) + HNO₃ S34 6 CuClPVP-BASF 4 to 10 E S35 3 Ag PVP-Aldrich 6 S36 4 AgBr PVP-Aldrich 4 E S37Pur- AgI PVP (AgI 25  chased nano from ChemPilots) S38 9 CuI (99.999)PVP-BASF + 4 HNO₃ S39 6 CuCl PVP-BASF <10 E S40 No AM Porous silicaSilica 0.5 material to 3 μm S41 13(1) CuI (98.5) Porous silica Silica 0to 20 μm S42 13(2) CuI (98.5) Porous silica, Silica 0.5 to 3 μm S43 5CuI(98) PVP-Aldrich 6 S51 16 CuI (99.5%) PVP-Aldrich 120  (Ground) S5216 CuI (99.5%) PVP-Aldrich 220  (Ground) S53 16 CuI (99.5%) PVP-Aldrich920 (bimodal (Ground) 170 and 1,500 nm) *“E” stands for those particleswhose size was estimated. Estimated particle size is based on comparisonto previously measured particle sizes for particles made according tothe same process.

Example 18 Efficacy Against P. aeruginosa of Various FunctionalizedParticles

Table 5 shows the reduction of P. aeruginosa by exposure to various typeof metal halide particles and their combinations, and also in differentconcentrations, sizes and surface modifications. All of these weretested with controls (meaning without metal halide particles or otherknown antimicrobial materials). The results from control are not shown,as they all uniformly showed either no growth or moderate growth ofmicrobes under the same conditions. Experiments were conducted induplicate. Further, in many cases, e.g., in Table 5, result R11 (at 24hr), the results show >4.41 log reduction. In the same table at 24 hrsthe result R40 also shows >5.19 log reduction. This does not imply thatthe result in the second case is more effective than in the first, allit says is that given a starting concentration of microbes, at thatpoint there were too few too count. Thus use of the symbol “>” in all ofthese tables means that the maximum log reduction for that experimentwas reached. That is to say, after the indicated time, there were noviable microbes seen. Sample number (starting with “S” in column 2) whenstated will correspond to the sample number in Table 4. If exactly thesame result number (Column 1, starting with “R”) is used in varioustables (Tables 5 to 10), then that corresponds to the same formulationand batch being tested for different microbes. For example R28 result inTable 5 was obtained on P. aeruginosa, and the same suspension was usedto obtain the R28 result against S. aureus in Table 6.

TABLE 5 P. aeruginosa Conc, PPM, Time Result Sample # Particles Ag, Cu15 min 30 min 1 hr 2 hr 6 hr 24 hr R7 S12 CuI 0, 594.32 >4.47 >4.47 >4.47 R8 S11 + S12 Ag + CuI 10,59  >4.47 >4.17 >4.47 >4.47 R9 S10 + S12 AgBr + CuI 10, 59 4.17 >4.47 >4.47 >4.47 R10 S11 + S12 Ag + CuI 10, 6  0.09 0.07 0.08 0.20R11 S12 CuI 0, 12 0.31 0.33 0.33 0.42 1.22 >4.41 R12 S11 + S12 Ag + CuI2, 12 0.3 0.3 0.42 0.46 1.32 >4.41 R13 S10 + S12 AgBr + CuI 2, 12 0.340.25 0.34 0.41 1.13 >4.41 R14 S11 + S12 Ag + CuI 10, 59 2.35 >4.41 >4.41 >4.41 >4.41 >4.41 R23 S17 CuI 0, 59 2.30 2.97 3.814.76 >4.77 R26 S26 CuI 0, 59 >4.65 >4.65 >4.65 >4.65 >4.65 R28 S28 CuI0, 59 >6.76 >6.76 >6.76 >6.76 >6.76 R30 S32 CuI 0, 59 4.11 >4.78 4.364.54 >4.78 R31 S33 CuI 0, 59 >4.19 >4.48 4.63 >4.78 >4.63 R32 S35 Ag 60,0  0.05 −0.05 −0.02 0.06 1.57 R33 S36 AgBr 60, 0  0.01 −0.11 −0.01 0.153.67 R34 S37 AgI 60, 0  0.01 0.01 0.06 0.19 0.29 R35 S38 CuI 0,60 >4.56 >4.56 >4.56 >4.56 >4.56 R36 S39 CuCl 0, 60 0.05 0.03 0.19 0.471.21 R37 S40 No AM 0, 0  0.24 0.2 0.04 0.02 material R38 S41 CuI 0, 190.97 2.32 >4.59 3.58 R39 S42 CuI 0, 15 1.50 3.89 >5.16 4.57 R40 S43 CuI0, 59 >5.04 >5.19 >5.19 >5.19 R48 S51 CuI 0, 59 >4.53 >4.53 >4.53 >4.53R49 S52 CuI 0, 59 4.38 >4.53 >4.53 >4.53 R50 S53 CuI 0, 59 3.913.84 >4.53 >4.53

Results on P. aeruginosa, a gram negative bacterium, are shown in Table5. Result R9 in this table shows that efficacy at much shorter times,i.e., at 15 minutes is surprisingly high. This high efficacy is seeneven in those formulations where only CuI is used, such as in R7. All ofthe above formulations use suspensions with a copper concentration of 59ppm.

When the copper concentration is dropped to 12 ppm, such as in R11, theefficacy at short times suffers, but one is still able to achieve highefficacy at 24 hrs. Addition of silver as silver metal or silver bromideto copper iodide (compare R11 to R12 or R13; or compare R7 to R8 or R9),does not improve the efficacy, showing that CuI by itself is quiteeffective.

Further, for P. aeruginosa, different surface modifications were used onCuI, such as PVP from Aldrich, PVP from BASF, VP-VA copolymer from BASF,Polyethylene glycol, and even acids for surface peptization (see resultsR26 to R31), and all of these show that each of these suspensions weremaximally effective. Comparison of results\One may also mix differentmetal halides or metal halide and a metal, and also particles withdifferent surface modifications with high efficacy against P. aeruginosaas shown in numerous results in this table.

Results R32 to R36 compare particles of various silver salts (AgBr andAgI), silver metal and various copper salts (CuCl and CuI), all of thesesurface modified with PVP and by themselves only, and all of them atmetal concentration of 60 ppm. This data clearly shows CuI has thehighest efficacy and the other materials show lower efficacy againstthis microbe.

Results R37 through R39 were on porous silica particles. R37 was forsilica particles with a size in the range of 0.5 to 3 μm which do nothave any CuI. Result R38 was for silica particles with a size in therange of 0 to 20 μm which had CuI infused by the method of Example 13(method 1). The copper metal content in these particles was 1.9% byweight. Result R39 was for silica particles with a size in the range of0.5 to 3 μm which had CuI infused by the method in Example 14 (method2). The copper metal content in these particles was 1.5% by weight.These were tested for antimicrobial effect in a suspension, where thesilica particles were added with and without CuI. The copperconcentration in samples R38 and R39 was 19 and 15 ppm respectively. Asexpected the sample without antimicrobial additive (result R37) did notshow antimicrobial properties. The other two showed a high efficacy.

Results R48 to R50 (on samples S51 to S53 respectively) are the resultsof suspension testing of particles made by wet grinding in the presenceof PVP comprising an aqueous solution using the process described inExample 16. These three samples were obtained from the same run butextracted at different periods of grinding. The average particle size ofthese three samples was 120, 220 and 920 nm respectively. The lastsample, S53 with an average particle size of 920 nm, had a bimodaldistribution with particles average sizes peaking at 170 and 1,500 nm.All of these show high antimicrobial efficacy, with the smallestparticle size sample (Result R48 on Sample S51) showing a great efficacyat shorter time periods.

Example 19 Efficacy Against S. aureus of Various FunctionalizedNanoparticles

TABLE 6 S. aureus Conc, PPM, Time Result# Sample # Particles Ag, Cu 15min 30 min 1 hr 2 hr 6 hr 24 hr R7 S12 CuI 0, 59 >4.07 >4.31 >4.31 >4.31R8 S11 + S12 Ag + CuI 10, 59  >4.31 >4.31 >4.31 >4.31 R9 S10 + S12AgBr + CuI 10, 59  >4.31 >4.31 4.07 >4.31 R10 S11 + S12 Ag + CuI 10, 6 0.05 0.04 0.06 0.09 R11 12 CuI 0, 12 0.79 0.95 1.35 1.81 2.96 >4.34 R12S11 + S12 Ag + CuI 2, 12 0.69 0.88 1.20 1.66 3.16 >4.34 R13 S10 + S12AgBr + CuI 2, 12 0.79 1.04 1.30 1.71 3.03 >4.34 R14 S11 + S12 Ag + CuI10, 59  0.58 2.71 >4.34 >4.34 >4.34 >4.34 R28 S28 CuI 0,59 >6.47 >6.47 >6.05 >6.47 >6.47 >6.47

Table 6 shows results from similar experimentation on S. aureus, a grampositive bacterium responsible for common staph infections. CuI in smallparticle size by itself or mixed with silver metal or silver bromide washighly effective as seen in results R7, R8 and R9. Similar conclusionfor S. aureus as for P. aeruginosa can be drawn on concentration of thecompounds, mixture of different metal halides or metal halide and ametal, and particles with different surface modifications.

Example 20 Efficacy Against S. mutans of Various FunctionalizedParticles

TABLE 7 S. mutans Conc, PPM, Time Result# Sample # Particles Ag, Cu 15min 30 min 1 hr 2 hr 6 hr 24 hr R27 S27 CuI 0,59 >4.75 >4.75 >4.60 >4.75 >4.75 >4.75 R28 S28 CuI 0,59 >4.75 >4.75 >4.75 >4.75 >4.75 >4.75

To test the broad efficacy of metal halides, and in particular forcopper iodide, we also tested functionalized particles of this materialagainst several other microbes. One of these is a strep bacterium S.mutans, commonly found in mouth infections. R27 and R28 in Table 7 showsthat CuI particles modified with PVP and the copolymer (VP-VA) bothresulted in effective reduction of populations of this bacteria.

Example 21 Efficacy Against S. enterica Typhimurium of VariousFunctionalized Nanoparticles

TABLE 8 S. enterica Typhimurium Conc, PPM, Time Result# Sample #Particles Ag, Cu 15 min 30 min 1 hr 2 hr 6 hr 24 hr R23 S17 CuI 0,59 >4.85 >4.85 >4.85 >4.85 >4.85

Table 8 shows that at 59 ppm, CuI surface modified with PVP showed ahigh degree of effectiveness (R23) against the microbe S. enterica whenused alone or in combination with AgBr modified with thiomalic andaspartic acids (R16). This was more effective as compared to AgBr alonewith a silver concentration of 10 ppm in the suspension (R15).

Example 22 Efficacy Against Penicillium of Various FunctionalizedNanoparticles

TABLE 9 Penicillium Conc, Experiment Sample PPM, Time # # Particles Ag,Cu 24 hr 48 hr 72 hr 96 hr R27 S27 CuI 0, 59 >3.98 >3.98 >3.98 >3.98 R28S28 CuI 0, 59 >3.98 >3.98 >3.98 >3.98

To examine the effectiveness of the inorganic metal salts against molds,experiments were done against Penicillium as shown in Table 9. R27 andR28 in this table show that CuI particles modified with PVP and thecopolymer (VP-VA) both resulted in effective reduction of this mold.

Example 23 Efficacy Against A. niger of Various FunctionalizedNanoparticles

Table 10 shows the results for another mold A. niger. The strongestresponse is shown by CuI (R35) by itself.

TABLE 10 A. niger Conc, PPM, Time Result# Sample # Particles Ag, Cu 6 hr24 hr 48 hr 72 hr 96 hr R33 S11 Ag 50, 0 −0.09 −0.01 0.01 0.00 −0.16 R34S10 AgBr 50, 0 0.06 −0.14 0.16 0.21 0.15 R35 S14 CuI   0, 295 0.06 0.820.77 1.43 1.99 R36 S10 + S14 AgBr + CuI  50, 295 −0.02 0.39 0.78 0.620.81

Example 24 Preparation of Coatings with CuI and their AntimicrobialTesting

Materials and Methods

For this example two sources for CuI were used. The first was bulkcopper iodide powder (99.5% Sigma Aldrich) and the second nano-particlesof CuI functionalized with PVP prepared from the acetonitrile processand isolated as a dry powder. For the nano-particles two high loadingsof CuI in PVP were prepared namely 60 and 50 wt % CuI in PVP. The CuIused was 99.5% from Sigma Aldrich and the PVP was 10,000 MW from SigmaAldrich. A typical high loading preparation was as follows.

To a liter pear shaped flask fitted with a stir bar was added 4.05 g ofCuI powder and 300 ml of anhydrous acetonitrile. This was stirred togive a pale yellow solution. In a separate flask fitted with a stir wereadded 4.05 g of PVP and 200 ml of anhydrous acetonitrile. This wasstirred for 2 hours to give a straw yellow colored solution. Whilestirring the CuI solution the PVP solution was slowly added to it togive a transparent yellow solution. Upon stirring at room temperaturethis solution slowly turned a light green color; this took about onehour for completion. This solution was dried under reduced pressure at30° C. to form a light green powder with a CuI content of 50 wt %. Thisprocedure was repeated except the initial CuI concentration wasincreased to 6.07 g to give a concentration of CuI in the powder of 60wt %.

Preparation of Urethane Coating Containing CuI

To a beaker was added 5 g of an aliphatic urethane 71/N aqueousdispersions (35% solids, maximum viscosity 200 cP) sold under thetradename of ESACOTE obtained from Lamberti SpA, (Gallarate, Italy). Tothis was added 0.118 g of CuI powder (99.5% from Sigma Aldrich,particles not functionalized). This was stirred vigorously and 0.1 g ofthe cross linking agent PZ28 (Polyfunctional Aziridine manufactured byPolyAziridine, LLC Medford, N.J.) was added to the coating formulation.The urethane coating was applied to stainless steel substrates 2″×2″ bybrush application and cured at room temperature for 12 hours followed bytwo hours at 70° C. The cured coating was transparent with a slightbrown tint. It was durable and hard with good chemical resistance toboth water and ethanol. The Cu⁺ content of the dried coating was 2.0 wt%. This procedure was repeated except using the nano-powders of CuIdescribed above to give coated surfaces with differentconcentrations/types of Cu⁺. These coated substrates were tested forantimicrobial activity against P. aeruginosa using a method as describedbelow. As a comparison point a metal coated with DuPont antimicrobial(commercial powder coating) ALESTA™ was also tested (obtained fromDupont, Inc. (Industrial Coatings Division, Wilmington, Del.)). Theantimicrobial materials in these coatings were zeolite particles (about2 to 3 μm in size) infused with silver and zinc ions.

Test coupons (50×50 mm) were prepared by spraying with 70% ethanol toreduce bacterial background presence. Sample coupons were allowed to airdry before re-spraying with 70% ethanol and allowed to dry completelybefore testing. Polyethylene (PE) cover slips (40×40 mm) were sterilizedvia bactericidal UV for 30 minutes per side.

These polymer coated surfaces were tested as discussed earlier using JISZ2801-2000. The coating compositions and the results are summarized inTable 11.

TABLE 11 Log₁₀ Reduction Wt % Cu⁺ Particle (P. aeruginosa) in CoatingType of CuI used size* 6 hr 24 hr 2.0 Bulk Powder 1 to 2 μm  0.31 ± 0.03 0.29 ± 0.08 (99.5%) 4.3 CuI nanoparticles 254 nm >5.69 ± 0.00 >5.69 ±0.00 (60 wt % in PVP) 3.0 CuI nanoparticles 241 nm >5.49 ± 0.17 >5.69 ±0.00 (50 wt % in PVP) 0.0 None −0.02 ± 0.10 −0.02 ± 0.05 DuPont None 2to 3 μm  0.89 ± 0.08  4.52 ± 0.00 Crystal Clear AM coating *Particlesize of CuI or the antimicrobial material (optical microscope used tocharacterize bulk powder).

These results show that functionalized CuI particles deliveredsignificantly better antimicrobial performance as compared to thecommercial antimicrobial coating, especially at the 6-hour mark. It isnotable that the use of CuI (as received) as non-functionalizedparticles in the coatings when used at about 2 μm in size did not resultin any perceived antimicrobial activity (see also Table 12, wherecoatings containing 1% or less Cu⁺ comprising functionalizednanoparticles were notably antimicrobial).

Example 25 Preparation of Urethane Coatings Containing Wet Ground CuIDispersion in Urethane (Emulsion) Resin

A sample of liphatic urethane 71/N aqueous dispersion was divided in twoparts. In one part CuI was added and ground to a small particle size fora duration of 240 minutes as described in Example 15 so that the smallerCuI particles being formed were functionalized by the PU dispersion.These two parts were then mixed in different proportions to vary theamount of copper in the coating formulation. As an example a formulationwhere these were mixed in a proportion of 50% each by weight was made asfollows. To a beaker was added 3 g of an aliphatic urethane 71/N aqueousdispersion was added 3 g of the CuI comprising dispersion. This wasmixed well to form a homogeneous material. While stirring 0.12 g of thecross linking agent PZ28 (polyfunctional aziridine manufactured byPolyAziridine, LLC Medford, N.J.) was added to this mixture. Theurethane formulation was applied to stainless steel substrates 2″×2″ bybrush application and cured at room temperature for 12 hours followed bytwo hours at 70° C. The cured formulation was transparent with a slightbrown tint. It was durable and hard with good chemical resistance toboth water and ethanol. The Cu⁺ content of the dried coating was 3.51 wt%. This procedure was repeated by varying the ratio of PU71/N to CuIurethane dispersion to give coated surfaces with differentconcentrations of Cu⁺ as listed in Table 12. These were tested againstP. aeruginosa as described in the above example, and the results areshown in Table 12. In this example, it should be emphasized thatpolyurethane 71/N aqueous dispersion is an emulsion of a hydrophobicurethane, as after it is coated and dried, this cannot be solvated inwater.

TABLE 12 Ratio PU:(CuI + Wt % Cu⁺ in Log₁₀ Reduction PU) (by weight)Dried Coating 6 hours 24 hours 10:90 6.33 >6.08 ± 0.05   >5.98 ± 0.0550:50 3.51 3.24 ± 0.05 >5.82 ± 0.05 75:25 1.76 3.71 ± 0.05 >5.76 ± 0.0590:10 0.70 3.24 ± 0.05 >5.98 ± 0.05 100:0  0.00 0.55 ± 0.05 −0.04 ± 0.08

The above results show that incorporation of functionalized CuIparticles in coatings which were prepared by grinding in a polymericemulsion process resulted in polymer-functionalized CuI particles havinghigh antimicrobial activity. The polymeric emulsion functionalized theCuI surfaces and stabilized the particles as it was pulverized. PUcoatings without the copper-based additive did not demonstrateantimicrobial properties, as demonstrated in the 100:0 result of Table12. Further, the antimicrobial activity increased with the increased CuIcontent. It is interesting to note that all of these coatings with CuIhad better performance at short times as compared to the commercialcoating in Table 11. Further, sample with less than 5% CuI (the 90:10)formulation resulted in high antimicrobial efficacy.

Example 26 Povidone-Iodine Plus Copper Iodide/PolyvinylpyrrolidoneAntimicrobial Solution

A copper iodide polyvinylpyrrolidone (PVP) powder is prepared bydissolving 0.0476 g of CuI (99.999% Sigma Aldrich) in 50 ml of anhydrousacetonitrile. To this solution is added 10 g of PVP (10,000 MW SigmaAldrich) and stirred to form a pale yellow solution. The acetonitrile isremoved under reduced pressure at 30° C. to form a pale green powder.This powder contains 0.158 wt % Cu⁺.

To 10 ml of a 10% solution of Povidone-iodine (CVS brand, obtained fromCVS Pharmacy, Tucson, Ariz.) is added 0.38 g of the CuI/PVP powderpreviously described to give a 60 ppm concentration of Cu⁺ in thesolution. This forms the Povidone-iodine-CuI/PVP antimicrobial solution.

Example 27 Topical Cream Comprising CuI Nanoparticles: Zone ofInhibition

To prepare this cream, functionalized CuI particles with two differentsizes were prepared in PVP.

For the first preparation, the particle size was 241 nm and was made bythe procedure described in Example 24 which used 10,000 molecular weightPVP from Sigma Aldrich. This is called 50% Powder (as this had 50% byweight of CuI in the dry powder).

For the second preparation, the particle size was predominantly 4 nm andwas prepared in the following fashion. To a reaction flask containing 80ml of anhydrous acetonitrile, (99.8% Sigma Aldrich Cat. #271004), wasadded 4.75 g of PVP (Luvitec™ K17 from BASF) and stirred to form a lightyellow solution. To this solution was added 0.25 g of CuI (99.999% SigmaAldrich Cat. #205540) and after stirring for 30 minutes this resulted ina clear pale green solution. Then the bulk of the acetonitrile wasremoved under reduced pressure at 30° C. to form a viscous paste. Thetemperature was then increased to 60° C. to completely remove thesolvent to give a pale yellow solid. Dynamic light scattering on adilute sample of the dispersion showed a mean particle size of 4 nm for85% of the particulate volume, and the others were larger. This had 5weight % of CuI in the dry powder, and was called 5% Powder.

The cream was prepared in a beaker by adding 0.06 g of Carbomer(obtained from Lubrizol Inc, Wickliffe, Ohio) and 2.0 ml of deionizedwater(18 Mohm-cm). This was mixed to give a slightly hazy non colorlessliquid. To this mixture was added 0.2 g of PVP (Sigma Aldrich, 10,000molecular weight) and the mixture stirred vigorously. The addition ofPVP caused a slight decrease in the viscosity. To this solution wasadded while stirring 1.96 g of CuI/PVP 50% Powder followed by 1.45 g ofCuI/PVP 5% Powder. The final concentration of Cu⁺ in the cream was 2.1wt %. This cream was tested against P. aeruginosa and S. aureus usingthe zone of inhibition method as described below.

Petri dishes for the test were prepared by dispensing 25 ml of sterileagar medium into sterile plates. Overnight cultures were diluted tofinal working optical density 600 nm of 0.100 and uniformly streakedover the agar using sterile swabs. Cylindrical plugs having a diameterof approximately 5.3 mm were removed from the solidified agar plates bymeans of a sterile cork borer. Approximately 75 μl of cream were addedto the wells. Triple antibiotic first aid ointment from WalgreensPharmacy (Walgreens Brand, obtained from Walgreens Pharmacy, Tucson,Ariz.) was used as a control material. This cream (control) listedBacitracin zinc 400 units, Neomycin 3.5 mg and Polymyxin B sulfate at5,000 units as active ingredients in white petrolatum. Plates asdescribed were incubated in a humidified chamber at 37° C. for 24 hoursat which time the plates were examined for bactericidal and growthinhibition effects.

Upon examination of the plates a slight bluish-green hue halo wasobserved around the wells along with a zone of inhibition for CuIcomprising creams. A three scale measure was used to determine the zoneof inhibition, “0” for no inhibition, which was indicated by completeabsence of the zone of inhibition; “1” as limited inhibition, where thezone diameter (including the well) was in the range of 6 to 8 mm; andsignificant inhibition designated as “2”, when this zone (including thewell) exceeded 8 mm. The results are shown in Table 13 below.

TABLE 13 Inhibition against Inhibition against Material P. aeruginosa S.aureus Control 0 2 Cream with CuI 2 2

The control cream is known to be effective against Gram positivemicroorganisms, and the results show the controls inhibited S. aureus,as expected. The CuI creams of the current formulation show equaleffectiveness against S. aureus. Against the Gram negative P.aeruginosa, the control creams were not expected to show efficacy, andthey did not. However, the CuI-based cream did show substantialeffectiveness, further bolstering the broad antimicrobial nature of theinvention.

Example 28 Preparation of CuI Particles Surface Modified bySodiumdodecylsulfate (SDS) by Grinding Process

CuI (99.5% from Aldrich) and SDS (Aldrich #436143) were used for thispreparation. The same mill that was used in Example 15 was used toprepare this sample. The mill parameters were: 4200 RPM, Pump=600 RPM,Media used=100 μm diameter in YZT, Grinding time=1260 min

Water was allowed to circulate with pump on at 25 rpm and the mill on at1000 rpm while 94.2854 g CuI (99.5%), and 17.142 g SDS were added (85.7%CuI and 14.3% SDS). This was done to prevent overloading or clogging themill. The pump and mill speed were then increased to 600 and 4200respectively. This mixture was ground at these speeds for 1260 minutesusing 4.13 kWh. A chiller was used to cool the slurry being ground. Apink mixture was removed from the mill and dried in a blowing furnacebecause the foaming action of SDS prevents drying on a rotaryevaporator. The product was dried in a covered pan at 70° C. until theproduct was completely dry. This formed a pink/tan solid powder with ayield of 107 g (97.3% yield). Table 14 shows the particle size fromdynamic light scattering measurements when this powder was redispersedin water. This table also shows the antimicrobial properties of theliquid suspension when tested at a copper concentration of 59 ppm. Theparticle size here is relatively large, which may have reduced itsefficacy at shorter times as compared to the results in Tables 5 and 6.

TABLE 14 Particle size (DSL) Antimicrobial activity Particle % poly-(59.07 ppm Cu), log₁₀ reduction Size (nm) dispersity Time P. aeruginosaS. aureus 372.2 59.4 15 min  3.60 ± 0.21  1.53 ± 0.08 1 hr  3.97 ± 0.30 3.57 ± 0.04 3 hr >4.66 ± 0.00 >4.50 ± 0.00 6 hr >4.66 ± 0.00 >4.50 ±0.00

Example 29 Preparation of Precipitated Porous Silica Infused with CuI

(a) Copper iodide (2 g, 99.5%, Aldrich) was added to a 250 ml roundbottom flask along with a stir bar and acetonitrile (40 ml) to give asaturated solution. This saturated solution was then left to stir atroom temperature for several hours. The resulting solution was a paleyellow color with a pale yellow precipitate.

(b) This CuI saturated solution was filtered via vacuum filtration usinga 0.8 μm MAGNA, nylon, supported plain filter paper by Osmonics.

(c) The clear, pale yellow filtered solution was added to a clean 250 mlround bottom flask with a stir bar and 3.5 g of porous silica (Sipernat22 LS, 9 μm in size, precipitated Silica with a specific surface area of180 m²/g, obtained from Evonik Industries). This solution was stirred at25° C. for one hour.

(d) The solution was again filtered via vacuum filtration using a 0.8 μmMAGNA, nylon, supported plain filter paper by Osmonics (Obtained fromFisher Scientific, Pittsburgh, Pa.). A white silica and CuI containingpowder was collected and was left to dry overnight at 100° C.

(e) Copper iodide (2 g, 99.5%) was added to a 250 ml round bottom flaskalong with a stir bar and acetonitrile (40 ml) to give a saturatedsolution. This saturated solution was then left to stir at roomtemperature for several hours. The resulting solution was a pale yellowcolor with a pale yellow precipitate.

(f) This CuI saturated solution was filtered via vacuum filtration usinga 0.8 μm MAGNA, nylon, supported plain filter paper by Osmonics.

(g) The clear, pale yellow filtered solution was added to a clean 250 mlround bottom flask with a stir bar and 3.5 g of porous silica+CuI whichwas prepared in step “d”. This solution was stirred at 25° C. for onehour.

The solution was again filtered via vacuum filtration using a 0.8 μmMAGNA, nylon, supported plain filter paper by Osmonics. A white powderwas collected and was left to dry overnight at 100° C. An analysisshowed that this powder was 76.6% silica and 23.4% CuI. Itsantimicrobial properties in a suspension at 59 ppm of Cu is shown intable 15, and it is likely that the availability of Cu+ions fromantimicrobial particles in porous particles is lower than from theassembly of individual nanoparticles, which leads to lower efficacy ascompared to the results in Table 5

TABLE 15 Antimicrobial activity (59.07 ppm Cu), log₁₀ reduction Time P.aeruginosa 30 min 3.23 ± 0.62 3 hrs 2.96 ± 0.35

Example 30 Preparation and Testing of Antimicrobial Powder Coatings

The coatings were prepared by first dry blending the functionalized CuIparticles (SDS functionalized particles as prepared in Example 28, orporous silica infused with CuI as prepared in Example 29) with acarboxylated polyester resin (Crylcoat 2471 obtained from Cytec,Woodland Park, N.J.) containing a crosslinking agenttriglycidylisocyanurate (TGIC, obtained from Aal Chem, Grand rapids,Mich.), a flow/leveling agent Powdermate 570 (obtained from TroyChemical, Newark, N.J.) and a degasser Powdermate 542 (obtained fromTroy Chemical). The concentration of CuI was varied. This mixture wasthen extruded in a two zone temperature process (zone 1=109° C. and zone2=86° C.) and roller cooled to form a ribbon. This ribbon was crushedand dry blended to form a fine powder. This powder was ultrasonicallyfed into a Corona gun for powder coating onto 2″×2″×0.025″ aluminumcoupons. The coated aluminum substrates were cured at 204° C. for tenminutes under ambient atmosphere. The various coatings had a thicknessranging from high 50 to 75 μm and had a gloss (at 60°) between 100.3 to126.3). The antimicrobial results are shown in Table 17. These coatingsare compared with coatings deposited from a commercial antimicrobialpowder material Alesta PFC609S9A from Dupont (Experimental Station,Delaware) which was also deposited in a similar fashion as above onsimilar substrates. These coatings have silver and zinc ions to provideantimicrobial properties. All of these coatings with antimicrobialmaterial (including the one from Dupont) resulted in antimicrobialsurfaces. However, at shorter times, all of the coatings with CuIprovided superior efficacy as seen by greater log reduction.

TABLE 17 Log₁₀ reduction of the microbe P. aeruginosa P. aeruginosa S.aureus S. aureus Sample (6 Hrs) (24 Hrs (6 hrs) (24 hrs) 0.25%Cu >5.63 >5.43 >4.77 >5.31 (with SDS) 1.0% Cu(with >5.63 >5.83 >5.72 >5.31 SDS) 3.0% Cu (with >5.63 >6.03 >5.72 >5.31SDS) 0.25% Cu (in >5.53 4.34 5.23 >5.31 Silica) DuPont AM 1.79 5.73 3.294.65 coating Standard −0.19 −0.59 0.16 0.57 polyester resin (No AM)The samples were cleaned after the evaluation by rinsing them twice inethanol, washing them with a dish washing liquid and followed by anothertwo rinses in ethanol. The antimicrobial effectiveness of the sampleswas evaluated against S. aureus. The results are shown in Table 18 anddemonstrate that the samples are durable to washing and repeated use.

TABLE 18 Log₁₀ reduction of the microbe S. aureus S. aureus Sample (6hrs) (24 hrs) 0.25% Cu (with SDS) 4.58 >4.65 1.0% Cu (withSDS) >5.35 >4.75 3.0% Cu (with SDS) >5.35 >4.65 0.25% Cu (in Silica)4.23 >4.31 Standard polyester resin (No AM) −0.09 0.53Another set of ground CuI/SLS was made where the proportion was 75/25 byweight. The grinding parameters were the same as in Example 28, but thegrinding time was reduced to 300 minutes. This was added to the powdercoatings as discussed above in a concentration of 0.25 and 0.05% Cu (asCuI). The coatings with 0.25% Cu had a slight haze, whereas coatingswith 0.05% Cu were clear. The results on the 0.25% coatings are shown inTable 19.

TABLE 19 Log₁₀ reduction of the microbe (S. aureus, ATCC#25923), 24hours Washed Sample Washed Washed 50 times Traetment Initial 1X 50 timesand scratched Washed with water >4.21 >4.31 >4.31 >4.31 Washed withWindex ® >4.21 >4.31 >4.31 >3.91 Washed withPine-sol ® >4.21 >4.31 >4.31 >4.31 Ultrasonicated in >6.01 >6.01 waterfor 5 minutes @ 20 KHz Pine-sol ® and Windex ® are commercial cleanersmade by Clorox (Oakland, CA) and by S.C. Johnson (Racine, WI)respectively. Each wash cycle with cleaners comprised of spraying ofcleaner and then covering the surface with a wipe by going in a zig-zagmotion horizontally, vertically and then horizontally. The surfaces werescratched with heavy duty scour pads, Target Brand, Obtained fromaTarget store in Tucson, AZ.

The results on coatings with 0.05% Cu are shown below in Table 20.

TABLE 20 Log₁₀ reduction of the microbe S. aureus P. Aeruginosa(ATCC25923) (ATCC 9027) Sample Type 6 hrs 24 hrs 6 hrs 24 hrs Coatingwith anti- 0.9 1.37 0.39 0.01 microbial additive Coating withanti- >3.59 >4.17 >3.86 >3.61 microbial additive Dupont AM coating1.82 >4.17 2.27 >4.16The results (Log₁₀ Reduction) on coatings with 0.05% Cu and 0.25% Cuagainst salmonella (S. typimurium, ATCC #23564) are compared to coatingswithout antimicrobial (AM) agent in Table 21.

TABLE 21 Coating Coating Coating Time without AM with 0.05% Cu with0.25% Cu 6 hours 0.06 ± 0.08 1.78 ± 0.25 >4.59 ± 0.28 24 hours  0.11 ±0.03 2.64 ± 1.10 >4.54 ± 0.35

Example 31 Formation of Functionalized Particles by Wet Grinding

The samples were ground in a wet grinding mill produced by NetzschPremier Technologies LLC (Exton Pa.), equipment model was Minicer®. Thegrinding beads were made of YTZ ceramic. The interior of the mill wasalso ceramic lined. The materials used for these preparations areoutlined in Table 22.

TABLE 22 Material Description AuI Gold iodide, Aldrich 398411 AgI Silveriodide, 204404 Bioterge Sodium capryl sulfonate (aq); BIOTERGE PAS-8S(obtained from Stepan, Northfield, IL) Chitosan Deacetylated chitin,medium molecular weight, Aldrich 448877 CuI Copper iodide 99.5% Aldrich03140 CuSCN Copper thiocyanate, Aldrich 298212 PEG Polyethylene glycolCARBOWAX ™ SENTRY ™ PEG 8000 NF, FCC Grade; Macrogol 8000 Ph. Eur.Granular, (obtained from Dow Chemical, Midland, MI) PVP-APolyvinylpyrrolidone Avg MW = 10,000, Aldrich PVP10 PVP-BPolyvinylpyrrolidone Avg MW = 10,000, Luvitex K17 57858045 (Obtainedfrom BASF, Germany) SDS Sodium dodecyl sulfate, Aldrich 436143 ZnO Zincoxide, Aldrich 251607 H2O Deionized water, 18 megaohm-cm AscorbicL-Ascorbic acid >99%, Aldrich 95210 Acid UV2-Hydroxy-4-(octyloxy)benzophenone 98%, Aldrich 413151 stabilizer IPAIsopropyl alcohol, 99.5% Aldrich 278475

Table 23 shows various samples which were processed along with theconditions under which these were made. During grinding operation, thegrinding head was chilled using a coolant at 5° C. However, depending onthe viscosity, volume of material being ground and grinding conditionsthe grinding liquid temperature varied between 10 and 30° C. Thequantity of grinding beads was measured volumetrically as approximately140 ml.

TABLE 23 Solids Proportion by Weight % Metal Total Media GrindingCompound, Functionalization Solids Water Mill Pump Size Time Sample %agent(s), % (g) (mL) (RPM) (RPM) (mm) (min) 1. CuI/PEG CuI, 15 PEG, 8510 100 4200 600 0.1 960 2. CuI/PEG/ CuI, 20 PEG, 77.61; 10 100 4200 6000.1 60 SDS SDS, 2.39 3. CuI/PVP CuI, PVP-B, 99.53 60.29 300 3800 500 0.1360 0.47 4. CuI/PVP CuI, 10 PVP-B, 90 10 100 4200 600 0.1 60 5. CuI/PVP/CuI, 20 PVP-A, 77.61; 10 100 4200 600 0.1 300 SDS SDS, 2.39 6. CuI/SDSCuI, SDS, 14.3 0.7 140 2500 350 0.3 420 85.7 7. CuSCN CuSCN, PVP-A, 90 1100 4200 600 0.1 172 10 8. AuI AuI, PVP-A, 99.79 5.01 100 4200 600 0.1120 0.21 9. AgI AgI, 10 PVP-A, 90 10 100 4200 600 0.1 1070 10. ZnO ZnO,10 PVP-B, 90 10 100 4200 600 0.1 60 11. CuI/CH CuI, 50 Chitosan, 50 2100 mL + 4200 600 0.1 60 (Chitosan) 2 g acetic acid 12. CuI/CH/PVP CuI,10 Chitosan, 10; 10 100 mL + 4200 600 0.1 60 PVP-B, 80 1.5 g acetic acid13. CuI/PEG/ CuI, Bioterge, 4.3; 3 200 4200 600 0.1 30 Bioterge 85.7PEG, 10 14. CuI/Ascorbic CuI, Ascorbic acid, 0.7 200 4200 600 0.1 30acid 85.7 14.3 15. CuI/UV CuI, 20 UV Stabilizer, 80 2.5 10 mL + 4000 6000.1 1000 Stabilizer 190 mL IPA 16. AgBr/PVP AgBr, PVP-B, 90 10 100 4000600 0.1 60 10

Table 24 shows the results of average particle size. Tables 25 and 26show antimicrobial activity of select samples against P. aeruginosa andS. aureus respectively. Some of these formulations were made to verifythe viability of grinding different materials with differentfunctionalizing agents and to see if these will result in particle sizeswith good antimicrobial activity. Under the specific processingconditions utilized for that sample, sometimes a bimodal or a trimodalparticle size distribution was seen (measured by light scattering). Inthose cases where most of the mass was represented by a single fraction,other fractions are not shown. Unless stated otherwise, theantimicrobial properties were typically measured at 59 ppm of metalconcentration (concentration in the testing solution). Theconcentrations of the functionalization agents in the testing solutionsare also shown in Tables 25 and 26.

By varying the conditions of grinding and the formulation composition itwas possible to vary the average particle size from about 3 to about1,000 nm. It was also possible to obtain larger particle sizes, butattention was focused on obtaining particles smaller than about 200 nm.In general long grinding times and small, concentration of the materialbeing ground favored the formation of smaller particles (e.g., seesample #3). It was also found, however, that it was possible to achieveattractive antimicrobial properties with modest grinding times (e.g.,see samples 2, 4 and 11 to 14). It is also possible to introduce largefractions of CuI (greater than 10%) relative to the functionalizingagents, e.g., in samples 6, 13 and 14 the amount exceeds 80%. Thisstands in contrast to most chemical syntheses of CuI (see Examples 7 to9) where the percentage of CuI to the surface functionalizing agent doesnot exceed 5% and is typically notably smaller than 5%

When such high concentration of functionalizing materials are used as inthe chemical synthesis route, then the addition of the functionalizedantimicrobial material to a matrix material involves the introduction ofa large amount of functionalizing material, This can often impactnegatively the properties of the end-products produced, particularly forsolid products.

It has also been demonstrated that it is possible to grind andfunctionalize other metal salts including metal halides, and metaloxides, e.g. CuSCN, AuI, AgI, ZnO and AgBr samples 7, 8, 9, 10 and 16respectively. Sample 15 shows preparation of CuI functionalized with aUV stabilizer.

TABLE 24 Particle Size Solids Proportion by Weight % Function- ParticleMetal alization Size* by Sample Compound, % agent(s), % Mass %  1.CuI/PEG CuI, 15 PEG, 85 95% is 10 nm  2. CuI/PEG/SDS CuI, 20 PEG, 77.61;83% is 26 nm, SDS, 2.39 17% is 140 nm  3. CuI/PVP CuI, 0.47 PVP-B, 99.5393% is 3 nm, 5% is 17 nm  4. CuI/PVP CuI, 10 PVP-B, 90 65% is 10 nm, 35%is 120 nm  5. CuI/PVP/SDS CuI, 20 PVP-A, 77.61; 89% is 6 nm, SDS, 2.3911% is 117 nm  6. CuI/SDS CuI, 85.7 SDS, 14.3 75% is 20 nm, 25% is 120 7. CuSCN CuSCN, 10 PVP-A, 90 75% is 180 nm, 25% is 50 nm  8. AuI AuI,0.21 PVP-A, 99.79 99% is 4 nm  9. AgI AgI, 10 PVP-A, 90 99% is 3 nm 10.ZnO ZnO, 10 PVP-B, 90 93% is 120 nm 11. CuI/CH CuI, 50 Chitosan, 50 22%is 14 nm, (Chitosan) 78% is 1371 nm 12. CuI/CH/PVP CuI, 10 Chitosan, 10;81% is 9 nm, PVP-B, 80 19% is 808 nm 13. CuI/PEG/ CuI, 85.7 Bioterge,4.3; 82% is 30 nm, Bioterge PEG, 10 18% is 150 14. CuI/Ascorbic CuI,85.7 Ascorbic acid, N/A acid 14.3 15. CuI/UV CuI, 85.7 UV Stabilizer,100% is 410 nm Stabilizer 14.3 16. AgBr/PVP AgBr, 10 PVP-B, 90 96% 744nm, 4% 165 nm

Some of the dry powders (after grinding was over and the particles weredried in a roto-evaporator) were examined under an optical microscope.The particles of the dried cluster were found to be in the range of 570nm to 2 microns for sample 6 and for sample 13 it was in the range ofabout 1 to 2 microns. This shows clusters of particles are formed upondrying, particularly when a polymeric agent (PEG in this case) ispresent.

TABLE 25 antimicrobial test results against P. aeruginosaFunctionalization Log₁₀ reduction of P. aeruginosa after given timeSample Metal, (ppm) agent(s) (ppm) 5 min 15 min 30 min 1 hr 3 hr 6 hr 1.CuI/PEG Not tested 2. CuI/PEG/SDS Cu, PEG, (688); SDS >4.77 ± 0.00 >4.77± 0.00 (59.07) (21) 3. CuI/PVP Cu, PVP-B, (37527) 4.33 ± 0.34  4.57 ±0.00 >4.42 ± 0.21 >4.57 ± 0.00 (59.07) 4. CuI/PVP Cu, PVP-B,(1595) >4.64 ± 0.00  >4.64 ± 0.00 >4.64 ± 0.00 (59.07) 5. CuI/PVP/SDSCu, PVP-A, (688); SDS  4.59 ± 0.00 >4.60 ± 0.00 (59.07) (1) 6. CuI/SDSCu, SDS, (30) 3.60 ± 0.21  3.97 ± 0.30 >4.66 ± 0.00 >4.66 ± 0.00 (59.07)7. CuSCN Cu, PVP-A, (1015) 0.51 ± 0.04  3.95 ± 0.21  4.88 ± 0.00 (59.07)8. AuI Au, PVP-A, 46034 >5.07 ± 0.00 >5.07 ± 0.00 (59.07) 9. AgI Ag,PVP-A, (196) 0.10 ± 0.09 −0.07 ± 0.15  0.19 ± 0.21 (10) Ag, PVP-A,(1159) (59.07) Ag, PVP-A, (3924) (200) 10. ZnO Not tested 11. CuI/CH Cu,Chitosan, (177) 1.36 ± 0.11 >4.60 ± 0.00  >4.60 ± 0.00 (Chitosan)(59.07) 12. CuI/CH/PVP Cu, Chitosan, (177); 1.63 ± 0.04 >4.60 ±0.00  >4.60 ± 0.00 (59.07) PVP-B, (1418) 13. CuI/PEG/Bioterge Cu,Bioterge, (9); PEG, (59.07) (21) 14. CuI/Ascorbic Cu, Ascorbic acid,(30) acid 59.07

TABLE 26 antimicrobial test results against S. aureus Metal,Functionalization Log₁₀ reduction of S. aureus after given time Sample(ppm) agent(s) (ppm) 5 min 15 min 30 min 1 hr 3 hr 6 hr 1. CuI/PEG NotTested 2. CuI/PEG/SDS Cu, PEG, (688); SDS 3.97 ± 0.00 >4.27 ± 0.00(59.07) (21) 3. CuI/PVP Cu, PVP-B, (37527) (59.07) 4. CuI/PVP Cu, PVP-B,(1595) 2.36 ± 0.06 >4.38 ± 0.00  >4.38 ± 0.00 (59.07) 5. CuI/PVP/SDS Cu,PVP-A, (688); SDS (59.07) (21) 6. CuI/SDS Cu, SDS, (30) 1.53 ± 0.08 3.57± 0.04 >4.50 ± 0.00 >4.50 ± 0.00 (59.07) 7. CuSCN Cu, PVP-A, (1015) 0.27± 0.06 0.56 ± 0.01  2.83 ± 0.07 (59.07) 8. AuI Au, PVP-A, (46034) 0(59.07) 9. AgI Ag, PVP-A, (196) 0.08 ± 0.05 0.01 ± 0.00  0.14 ± 0.00(10) Ag, PVP-A, (1159) 0.59 ± 0.02  3.94 ± 0.10 (59.07) Ag, PVP-A,(3924) >4.71 ± 0.00  >4.71 ± 0.00 (200) 10. ZnO Not tested 11. CuI/CHCu, Chitosan, (177) (Chitosan) (59.07) 12. CuI/CH/PVP Cu, Chitosan,(177); (59.07) PVP-B, 1418 13. CuI/PEG/Bioterge Cu, Bioterge, (9); PEG,0.019 ± 0.06 1.68 ± 0.07 >4.53 ± 0.00 (59.07) (21) 14. CuI/Ascorbic Cu,Ascorbic acid, (30) >4.60 ± 0.00 >4.60 ± 0.00  >4.60 ± 0.00 acid (59.07)

The antimicrobial properties of the samples in Tables 23 and 24 areshown in Tables 25 and 26. Table 25 shows the antimicrobial propertieswhen tested against P. aeruginosa and Table 26 shows the antimicrobialproperties against S. aureus. Some materials were tested for bothmicrobes and several were only tested for one of them. Goodantimicrobial properties were obtained with the AuI suspensions.However, such suspensions were black in color and for those objectswhere color is an issue; this material will not meet the productrequirements. The tests for AgI were carried out at 10, 59 and 200 ppmAg and for CuI at 59 ppm Cu. These results on S. aureus in Table 26 showthat AgI was quite ineffective at 10 and 59 ppm Ag, whereas it showedgood antimicrobial property at 200 ppm. This shows that copper iodide isa more effective antimicrobial material as compared to silver iodide atlower concentrations (see several results on CuI at 59 ppm) in thistable and also results presented previously (e.g., Tables 5 and 6).

It was also found that CuI exhibited greater antimicrobial effectivenessat short times (e.g., 15 minutes) than CuSCN (compare sample 3 vs sample7 in Table 25), although CuSCN exhibited attractive antimicrobialproperties at longer times. Chitosan is not soluble in water, but it issoluble in water when a small amount of acetic acid was added, and hencecould be used as a functionalization agent in aqueous media. Chitsonfunctionalized CuI (sample 11) exhibited high antimicrobialeffectiveness in times as short as 15 minutes. CuI functionalized withascorbic acid exhibited outstanding antimicrobial effectiveness in timesas short as after 5 minutes (see sample 14 in Table 26). In severalcases more than one functionalization agent was used, e.g., samples 2,5, 12 and 13. All of these produced attractive antimicrobialeffectiveness.

Although the copper concentration (as copper salt) in most formulationswas 59 ppm, changes in the copper concentration would lead to changes inantimicrobial effectiveness. For example, increasing the copperconcentration would produce increased antimicrobial effectiveness at agiven time and comparable antimicrobial effectiveness at shorter times.

Example 32 Antimicrobial Activity Against Trichophyton mentagrophytesFungus

T. mentagrophytes is a common nail fungus. To test the efficacy of theAM material, CuI nanoparticles functionalized with PVP were madefollowing Example 24. The proportions of the materials used weredifferent. 300 ml of acetonitrile, 60 g of PVP along with 0.2856 of CuIwas used. The particle size of the functionalized particles was 6 nm.The log₁₀ reduction in the fungus using a liquid suspension with Cuconcentration at 59 ppm (as CuI) was evaluated at 6, 24 and 48, hr andwas found to be 1.02, 2.93 and 2.99, respectively, which shows a highdegree of effectiveness.

Example 33 Wound Dressing Preparation and Antimicrobial Testing

(a) Solution for Preparation of Wound Dressings without AntimicrobialMaterial

A solution was made with (a) 1.62 g sodium carboxymethyl cellulose(molecular weight (Mw) 700,000 obtained from Sigma Aldrich, Cat#419338)and (b) 80 g DI-H2O. This solution was stirred while heating at 70° C.to give a clear, viscous, colorless solution.

(b) Solution for Preparation of Wound Dressings with Functionalized CuIParticles (Resulted in 1 wt % Cu (as CuI) in Dry Solid)

A solution was made with (a) 0.0590 g CuI/PEG/Bio-terge Powder (28.57%Cu (as CuI) in powder), prepared as Sample 13 in Example 31 except thatthe grinding time was 13 minutes instead of 30 minutes (the average CuIparticle size was about 320 nm with polydispersity being 168%), (b) 80 gDI-H2O. This solution was stirred at room temperature and sonicated togive an opaque, white solution. At the end of this process, 1.62 gsodium carboxymethyl cellulose (molecular weight (Mw) 700,000). Thissolution was stirred while heating at 70° C. to give an opaque, viscous,slightly green solution.

(c) Preparation of Wound Dressing

One ply, white Kimtech Pure CL5 #06179, 50% rayon/50% polyestercleanroom wipes from Kimberly Clark Professional (Roswell, Ga.) were cutinto 2″×2″ pieces to use as gauze pieces for coating the above solutionsfor testing of wound dressings. The 2″×2″ gauze pieces were firstweighed before coating. They were then placed on a piece of glass andwere pre-wetted by hand with 0.9 ml DI-H2O using a syringe. Solutionsused for the wound dressing application were prepared as given below and1 ml volume of one of these solutions was then evenly applied to thepre-wetted wipe by hand using a syringe.

The coated gauze pieces were then dried in the oven for 30-40 minutes at70° C. Once dried the gauze pieces were removed from the glass and wereweighed again to determine the total solids content. Applying 1 ml ofthe coating solutions to the gauze gave an average solid content of 0.02g. Wipes were also prepared with solids content higher than 0.02 g,including single and multiple coating applications. After coating, thestandard gauze pieces (no antimicrobial) were white in color and thecopper containing gauze pieces were a pale green color. These coatedgauze pieces were then tested against P. aeruginosa as follows.

(d) Testing of Dressings Against P. aeruginosa

A single colony of P. aeruginosa was cultured overnight to stationaryphase in tryptic soy broth (TSB). The following day, the culture wasdiluted in TSB to read 0.1 optical density in a Synergy 2 reader (fromBiotek Instruments Inc, Winooski, Vt.). Following this, 0.25 ml ofculture was plated onto petri dishes containing tryptic soy agar (TSA).Gauze samples were then placed onto individual plates, one sample perplate. The total solid content on each gauze piece averages 0.02 g, withthe copper content (in the form of CO being 1% of this mass. Eachsection was pressed firmly onto the agar on the plate to ensurehomogeneous surface contact. The bacteria in contact with the gauze wereallowed to grow for 72, and 96 hours, one plate per time-point. Aftereach time-point the respective gauze sample was removed and the newlyexposed area was swabbed with a sterile loop, which in turn was spreadover a clean agar plate. This was allowed to grow for 24 hrs, afterwhich visual inspection of the plate produces the followingobservations: 72 hrs Cu-gauze completely killed the bacteria originallyplated under it, white the standard gauze displayed a heavy bacterialgrowth. The 96 hour gauze assay produced results identical to the 72 hrtesting.

Example 34 Comparison of PU Coatings Made by Grinding CuI in Emulsion,Vs, Grinding CuI with SDS and then Adding these to the Emulsion

In this preparation, CuI was ground with SDS (see Example 28). Thecomposition after grinding was dried and then added to the polyurethaneemulsion described in Example 24. In this example the CuI was not groundwith the emulsion, but particles functionalized (pre-functionalized)with the surfactant were added and mechanically mixed into the PUemulsion. These were then coated on 5 cm×5 cm stainless steel couponsand evaluated for antimicrobial efficacy with and without CuI additive.The samples with CuI had a copper concentration of 1% in the drycoating. The results in Table 33 show that these samples wereantimicrobial. These samples can be compared to coatings prepared bygrinding CuI in PU emulsion, where this data is shown in Table 34.Samples produced by both methods exhibited very attractive antimicrobialproperties.

TABLE 27 Pre-functionalized CuI particles added to PU coating emulsionLog₁₀ Reduction P. aeurginosa Log₁₀ Reduction S. aureus Time With CuIWithout CuI With CuI Without CuI 24 hr 4.05 −0.49 >4.47 0.21

TABLE 28 Functionalized particles formed by grinding CuI in PU coatingemulsion Log₁₀ Reduction P. aeurginosa Log₁₀ Reduction S. aureus TimeWith CuI Without CuI With CuI Without CuI 24 hr >5.04 −0.49 >5.15 0.15

Example 35 Nail Polish with Antimicrobial Additive and Testing

In order to demonstrate the incorporation of antimicrobial particles into a nail polish, a commercial water based nail polish was evaluated. Awater-based nail polish WaterColors Clear water-based nail enamel, wasobtained from Honeybee Gardens Inc. (Leesport, Pa. The ingredients fromthe labels of these products were listed in Table 29.

TABLE 29 Ingredients Water, water-miscible acrylic, polyurethane formersand thickeners, non-ionic soaps. May contain: ultramarine blue, carmine,mica, iron oxides, and/or titanium dioxide

The weight percent solids of the nail polish was determined by allowinga measured amount to dry in air for greater than 24 hours at ambienttemperature and determining the weight loss upon drying.

The particles used were prepared by the grinding method with acomposition of 85.7% CuI and 14.3% Bioterge PAS-8S. The grindingconditions are shown in Table 30. The average particle size was 320 nm.Dry copper iodide based antimicrobial powders were incorporated in thenail polishes at 1 wt % Cu (3 wt % CuI) by mechanical mixing.

TABLE 30 Solids Proportion by Weight % Metal Total Media GrindingCompound, Functionalization Solids Water Mill Pump Size Time % agent(s),% (g) (mL) (RPM) (RPM) (mm) (min) CuI, 85.7 Bioterge, 14.3 3 200 4200600 0.1 30

Nail polish with the antimicrobial additive were coated on 2-inchsquare, stainless steel substrates and allowed to dry for greater than24 hours. Nail polishes without the antimicrobial additive were coatedin the same fashion to serve as standards. All of these coatings wereevaluated for antimicrobial activity in the manner discussed earlier forother coatings. Over 24 hour period the control sample showed a log₁₀reduction of −1.16 (which shows growth), while the reduction in sampleswith the antimicrobial additive was 5.89. This shows a strongantimicrobial activity in samples with functionalized CuI particles.

Example 36 Preparation of Antimicrobial CuI Infused in Porous Silica andTreated with Surfactant

Copper iodide (7.89 g) was added to a 1 L pear shaped flask along with astir bar and acetonitrile (400 ml). This solution was then left to stirat room temperature for several hours. The resulting solution was clearand pale yellow in color.

The clear, pale yellow solution was then mixed with 25 g of Zeothix™265, a 3 μm silica (obtained from Huber). This solution was left to stirfor one hour at room temperature to give a viscous, milkywhite/off-white solution. This solution was then dried on the rotaryevaporator at room temperature, 30° C. and 60° C. to give a pink powder.

The resulting pink powder was then dispersed in 300 ml of deionizedwater along with 0.3945 g Stepanol™ WA-100 (sodium lauryl sulfateobtained from Stepan). The solution was stirred at room temperature fortwo hours and was a milky, pale yellow color. The solution was thendried overnight in the oven at 85° C. to give a pale green/orange/brownsolid. When well mixed the solid was tan in color. This powder can nowbe used as an additive to polymeric and liquid antimicrobialformulations.

Example 37 Copper (I) Iodide Particle Dispersion Formation andStabilization Using Water Soluble and Insoluble Polymers

To a 250 ml round bottom flask fitted with a stir bar and stopper wasadded 0.123 g of copper iodide, 50 ml of anhydrous acetonitrile and 1.0ml of poly(dimethylsiloxane). The poly(dimethylsiloxane) had a formulaweight of 162.38, boiling point of 101° C./760 mmHg and a viscosity of0.65 cST. The mixture was stirred at room temperature for 2 hours togive a pale green/blue solution. To this solution was added 2.578 g ofpolyvinylpyrrolidone with an average molecular weight of 10,000. Uponstirring this resulted in a green solution. The volatiles were removedslowly under reduced pressure (87 mmHg) at 25° C. and afterapproximately 4 hours a viscous slurry was obtained. The vacuum wasincreased to 5 mmHg and the bath temperature increased to 30° C. andafter 30 minutes a fine dry green powder was obtained. It appeared thatany excess poly(dimethylsiloxane) which was not attached to the surfaceof the particles was removed during the drying process. This powder wasdispersed in 25 ml of de-ionized water by stirring to give an opaquewhite dispersion. This dispersion without agitation was stable for over24 hours at room temperature. Dynamic light scattering analysis on adiluted sample of the dispersion gave an average particle radius of 160nm.

Example 38 Formation of Fluorosurfactant Functionalized Copper IodideParticles and their Use in Coatings

200 mL deionized water with 1.5 g 3M Novec FC 4430 (perfluorobutanesulfonate based surfactant from 3M as surface functionalizer) and 8.5 gcopper iodide were processed in a ceramic ball mill (see Example 15)using 100 micron yttria stabilized zirconia grinding media at a millspeed of 4200 RPM and recirculation pump speed of 600 RPM for 180minutes to form an opalescent milky green dispersion. This aqueousdispersion was concentrated by removing water under reduced pressure. Todisperse the particles in an organic solvent, a small amount was driedto a green and grey, tacky solid. This material disperses well in methylethyl ketone (MEK). This material also redisperses well in water.Dynamic light scattering showed that the average particle size in waterwas 150 nm and in MEK it was 100 nm. This material can be used as anantimicrobial additive both in coating and other products formulated inwater based systems and solvent based systems which are compatible withMEK.

To test its use in coatings, this material was added to a water basedpolyurethane coating formulation PU-73 (aliphatic urethane aqueousdispersion (35% solids) sold under the Tradename of ESACOTE™ obtainedfrom Lambeth SpA, (Gallarate, Italy)). 50.0 g of this urethanedispersion was mixed with 1.0 g PZ-28 crosslinking agent (polyfunctionalaziridine manufactured by PolyAziridine, LLC Medford, N.J.). This wascoated on an aminosilane primed substrate by dip coating and cured for 2hours at 70° C. to form a clear antimicrobial coating. The amount ofcopper was 0.25% (as copper iodide, similar to Example 25). In a similarfashion an acrylic antimicrobial coating was made from an MEK basedsystem with copper content (as copper iodide) of 0.25% cured by UV.These coatings were clear.

Example 39 Formation of Antimicrobial Solvent Based Coatings with CuIFunctionalized by Aminosilane

Surface functionalized CuI additive was made forming a solution of 0.560g 3-Aminopropyltriethoxysilane (APTES), 20 mL acetonitrile, 0.560 g CuI.This was stirred at room temperature and formed a brown solution.Acetonitrile was partially removed under reduced pressure to form adispersion of CuI particles in a concentration of 12.5% by weight whichwere functionalized by APTES. The weight fraction of APTES in thisformulation was also 12.5 wt %. This additive was soluble in methylethyl ketone (MEK) for use as an additive in coatings.

Example 40 Formation of Citric Acid Functionalized Copper IodideParticles and Formation of an Antimicrobial Solution

200 mL deionized water was mixed with 1.5 g citric acid (surfacefunctionalizing agent) and 8.5 g copper iodide. This was processed bygrinding in a ceramic ball mill using 100 micron yttria stabilizedzirconia as in Example 28 for a period of 180 minutes to form a milkywhite dispersion. This was diluted in water to result in anantimicrobial solution. Solutions were produced with copperconcentration ranging from 0.97% by weight down to 10 ppm by weight.

Example 41 Preparation of an Antimicrobial Cleaning (Disinfectant)Solution

1.36 g sodium lauryl sulfate (functionalizing agent), 25.7 g CuI, and257 mL deionized water were combined and processed in a ceramic ballmill as described in Example 28, with a pump speed of 100 RPM for 1300minutes to form a milky white dispersion of surface functionalized CuIat 6.550 wt % solids.

This was combined with 5% aqueous solution of citric acid to form a 60ppm Cu dispersion at pH of 2 to form an antimicrobial solution which maybe applied by putting them in wipes or applied on surfaces, e.g., byspraying. Dynamic light scattering showed that the average particle sizewas 100 nm after aging for one week.

Another cleaning solution was formed by taking the above and adding avinyl acetate-PVP copolymer (VA64 from BASF)) to a final concentration3400 ppm. This polymer would leave a film on the surface (film former)after the solution is wiped and or dried with trapped antimicrobialparticles so that the surface will continue to be microbe resistant longafter the cleaning/application of this material. These cleaningsolutions may also be formed by adding porous particles withantimicrobial additives loaded in the pores (see Example 36)

Example 42 Mill with Water-Acetonitrile Mixture

4.25 g CuI, 0.75 g sodium lauryl sulfate (surface functionalizer) wascombined with 30 g acetonitrile, 170 g deionized water, This mixture wasprocessed in a ceramic ball mill using 100 micron yttria stabilizedzirconia grinding media at a mill speed of 4200 RPM and recirculationpump speed of 600 RPM for 300 minutes to form a foamy, milky dispersion.Upon completion of the above process additional 200 mL of deionizedwater was added and milling continued for 30 minutes to form anopalescent, foamy, white dispersion. This dispersion (in liquid form orafter drying) forms additive to liquid or solid formulations andproducts.

Example 43 Antimicrobial Solvent Based Nail Polish

A mixture of 42.5 g CuI and 7.5 g Novec FC 4430 (3M) in 200 ml deionizedwater was milled for 1000 minutes at 4200 rpm mill speed with a pumpspeed of 600 rpm using the 100 μm YZT media. Other milling details wereas in Example 28. This dispersion, after milling was then dried on therotary evaporator at 40° C. The resulting solid was green in color.

The solvent based nail polish used was Nina Ultra Pro Salon FormulaSuper Dry Topcoat #709290 (produced by Cosmetic Design Group, Culvercity, CA). The nail polish was clear and colorless and was found to havea solids content of 25.93%.

The CuI/Novec FC 4430 additive (0.0018 g) was mixed with 0.5 mlacetonitrile and 0.25 ml isopropanol and was easily dissolved at roomtemperature with stirring. This solution was clear and colorless. TheNina Ultra Pro Salon Formula Super Dry Topcoat (2 g) was added to theCuI/Novec FC 4430 solution and was left to stir for 10 minutes to give aclear, colorless solution.

A 5 cm×5 cm aluminum substrate was coated with the Nina Ultra Pro SalonFormula Super Dry Topcoat containing the CuI/Novec FC 4430 additive fromabove. One coating was painted by hand and was left to dry at roomtemperature. The coating was clear and colorless. A coating of NinaUltra Pro Salon Formula Super Dry Topcoat with no additive was alsopainted by hand onto a 5 cm×5 cm aluminum substrate and was left to dryat room temperature. This coating was also clear and colorless. Uponexamination, the coating with the CuI/Novec FC 4430 additive wasindistinguishable from the polish coating with no additive.

Example 44 Preparation of Masterbatch and their Incorporation onThermoplastic Products

300 mL deionized water with 6.25 g sodium lauryl sulfate and 118.75 gcopper iodide were processed in a ceramic ball mill (see example 15)using 100 micron yttria stabilized zirconia grinding media at a millspeed of 4200 RPM and recirculation pump speed of 600 RPM for 240minutes to form a milky white dispersion. 13.97 g PEG (Carbowax 8000,Dow) was added to the slurry and processed for an additional 120minutes. This dispersion was dried to form a pink powder by removingwater under reduced pressure.

This material was incorporated into a thermoplastic polyester(crystalline polyethylene terephtlate-fiber grade) masterbatch. Twomasterbatches were made by incorporating 7 and 17.6% of the above blendin virgin PET. Incorporation of these masterbatches in a concentrationof 5% in additional PET to make antimicrobial PET results in copperconcentration of 0.1 and 0.25%, respectively.

Example 45 Formation of Block Copolymer Functionalized Copper IodideParticles and their Use in Coatings

300 mL deionized water with 20 g DisperBYK-190 (solution of highmolecular weight block copolymer with pigment affinic groups from BYKUSA Inc, Wallingford, Conn.) and 80.0 g copper iodide were processed ina ceramic ball mill (see Example 15) using 100 micron yttria stabilizedzirconia grinding media at a mill speed of 4200 RPM and recirculationpump speed of 600 RPM for 1000 minutes to form an opalescent milky greendispersion. This aqueous dispersion was concentrated by removing waterunder reduced pressure. Dynamic light scattering showed that the averageparticle size in water was 150 nm. This concentrated dispersion can bedispersed in water based coating formulation. When a dilute aqueousdispersion of this material was tested for antimicrobial properties(with copper concentration being 59 ppm), in 30 minutes, the log₁₀reduction for P. aeruginosa (ATCC 9027) was >4.93, and the log₁₀reduction for S. aureus (ATCC 25923) was 3.42.

To test its use in coatings, this material was added to a water basedpolyurethane coating formulation PU-73 (aliphatic urethane aqueousdispersion (35% solids) sold under the Tradename of ESACOTE™ obtainedfrom Lambeth SpA, (Gallarate, Italy)). 50.0 g of this urethanedispersion was mixed with 1.0 g PZ-28 crosslinking agent (polyfunctionalaziridine manufactured by PolyAziridine, LLC Medford, N.J.). This wascoated on an aminosilane primed substrate by dip coating and cured for 2hours at 70° C. to form a clear antimicrobial coating. The amount ofcopper was 0.25% (as copper iodide, similar to Example 25).

Example 46 Formation of Polyamine Amide and Acidic PolyesterFunctionalized Copper Iodide Particles

200 mL ethanol with 0.5 g Anti-Terra-U (solution of a salt ofunsaturated polyamine amides and low molecular weight acidic polyestersfrom BYK) and 10.0 g copper iodide were processed in a ceramic ball mill(see Example 15) using 100 micron yttria stabilized zirconia grindingmedia at a mill speed of 4200 RPM and recirculation pump speed of 600RPM for 180 minutes to form an opalescent ethanol green dispersion. Thisdispersion was dried to form a pink powder by removing water underreduced pressure. This powder disperses well in various organic solventsincluding butyl acetate. When a dilute aqueous dispersion of thismaterial was tested for antimicrobial properties (with copperconcentration being 59 ppm), in 30 minutes, the log₁₀ reduction for P.aeruginosa (ATCC 9027) was >4.93

Example 47 Formation Acidic Polyester Functionalized Copper IodideParticles

300 mL ethanol with 5.0 g BYK-W 985 (solution of acidic polyester fromBYK) and 92.5 g copper iodide were processed in a ceramic ball mill (seeExample 15) using 100 micron yttria stabilized zirconia grinding mediaat a mill speed of 4200 RPM and recirculation pump speed of 600 RPM for1000 minutes to form an opalescent milky green dispersion. This aqueousdispersion was dried to form a pink powder by removing ethanol underreduced pressure.

Example 48 Formation of Alkylol Ammonium Salt Copolymer (Ionic Polymer)Functionalized Copper Iodide Particles and their Use in Coatings

200 mL ethanol with 1.85 g DisperBYK-180 (alkylol ammonium salt of acopolymer with acid groups from BYK) and 10.0 g copper iodide wereprocessed in a ceramic ball mill (see example 15) using 100 micronyttria stabilized zirconia grinding media at a mill speed of 4200 RPMand recirculation pump speed of 600 RPM for 330 minutes to form anopalescent milky green dispersion. This ethanol dispersion is compatiblewith water based coatings and many solvent systems. When a diluteaqueous dispersion of this material was tested for antimicrobialproperties (with copper concentration being 59 ppm), in 30 minutes, thelog₁₀ reduction for P. aeruginosa (ATCC 9027) was >4.78.

To test its use in coatings, this dispersion was added to a water basedpolyurethane coating formulation PU-73. 50.0 g of this urethanedispersion was mixed with 1.0 g PZ-28 crosslinking agent. This wascoated on an aminosilane primed substrate by dip coating and cured for 2hours at 70° C. to form a clear antimicrobial coating. The amount ofcopper was 0.25% (as copper iodide, similar to Example 25). In a similarfashion an acrylic antimicrobial coating was made from an MEK basedsystem with copper content (as copper iodide) of 0.25% cured by UV.These coatings were clear.

The acrylic coatings were tested for their antimicrobial properties byevaluating them against S. aureus (ATCC #25923) using JI52801-2000 asdescribed earlier. The acrylic coating without the antimicrobialadditive showed a decrease in this strain of 0.10±0.11 and 1.05±0.92log₁₀ reductions in a period of 6 and 24 hr respectively, for the sametime periods coatings with antimicrobial additive (0.25 wt % copper)resulted in reductions of 3.47±0.61 and >4.40±0.00.

Example 49 Formation of Copper-Silver-Iodide-Bromide Solid Solution forWound Dressings (1 wt % Cu (as CuI) in Dry Solid)

30 mL acetonitrile, 0.066 g silver bromide, 0.933 g copper iodide, and31.1 g PVP-10K were stirred to form a clear green solution. Thissolution was dried to form a white powder by removing acetonitrile underreduced pressure. This powder was dispersed in water. This aqueousdispersion was used to form a wound dressing as in Example 33c. This wastested as in Example 33d. A complete kill of bacteria was observedwithin 24 hours.

Example 50 Formation of Copper-Potassium-Iodide Solid Solution for WoundDressings (1 wt % Cu (as CuI) in Dry Solid)

30 mL acetonitrile, 1.0 g potassium iodide, 1.0 g copper iodide, and32.33 g Copolymer Vinyl acetate-Vinyl pyrrolidone (Luvitec VA64, BASF,Germany) were stirred to form a clear orange solution. This solution wasapplied to form a wound dressing. Upon drying, copolymer functionalizedCuI particles were formed. This wound dressing was tested as in Example33d. A complete kill of bacteria was observed within 24 hours. Apotassium iodide wound dressing was similarly prepared and did notappear to kill bacteria following the same procedure.

Example 51 Formation of Acidic Polyester Modified Copper Iodide SilicaBlend

400 mL deionized water, 15 g acidic polyester modified copper iodide(see Example 46), and 15 g 3μ silica (Zeothix 265) were processed in aceramic ball mill (see Example 15) using 100 micron yttria stabilizedzirconia grinding media at a mill speed of 4200 RPM and recirculationpump speed of 600 RPM for 180 minutes to form an opalescent milkydispersion. This dispersion was dried by removing water under reducedpressure to form a gray to pink solid.

Example 52 Formation of Antimicrobial Dental Adhesive with an InorganicCopper Salt

Kerr Optibond XTR dental adhesive (Kerr Corporation, Orange, Calif.) wascombined with an inorganic copper salt. This copper salt was surfacefunctionalized (copper iodide functionalized with bioterge, see Example35). Ethanol (solvent) was added to the adhesive to reduce its viscosityin order to effectively mix the functionalized CuI particles. Ethanolwas removed under reduced pressure to form a viscous CuI containingdental adhesive paste. This dental adhesive was coated on to aluminumsubstrates and cured under UV. The substrates were further cured at 130°C. under nitrogen at 60 psi for 20 minutes using a belleGlass™ HP CuringUnit (Kerr Corporation, Orange, Calif.).

Dental adhesive coatings were formed at 0.5, 0.25, and 0.0% Cu by weight(as CuI). These coatings were evaluated against streptococcus mutansover a period of six hours using JIS2801-2000 procedure as describedabove. The log₁₀ reductions of the microbes in these coatingswere >3.93, >3.81 and 0.59 respectively.

Example 53 Improved Dispersibility of CuI by Addition of Soluble IodideSalt

To a round bottom flask was added 30 mL of anhydrous acetonitrile, 15 gof PVP 10K. This was stirred to form a clear solution. To this was addedcopper iodide or copper iodide along with sodium iodide. Clear solutionswere formed in all cases. Both of these solutions was dried underreduced pressure and redispersed separately in water and linear alcoholsmethanol, ethanol, propanol, and butanol. These solutions were monitoredfor clarity (stability) for 1 month as described in the table below.

TABLE 31 Redisperses Redisperses Sample CuI Salt, PVP in Water as a inAlcohol as a ID (g) NaI (g) 10K (g) clear dispersion clear dispersion A0.367 0.133 15 Yes, Stable Yes, Stable B 0.367 0.000 15 No No

Example 54 Improved Dispersibility of a Salt with Low Water Solubilitywith Addition of a High Water Solubility Salt

The use of sodium iodide (a water soluble salt) was evaluated to improvedispersability of functionalized copper iodide particles. A clearsolution was made with 200 ml of deionized water and 0.399 g of NaI. Tothis solution 1.01 g of copper iodide was added. To this mixture 45 g ofPVP 10K (PVP with a molecular weight of 10,000) was added and still CuIdid not dissolve. 200 mL deionized water with 45 g PVP 10K, 1.101 gcopper iodide, and an amount of sodium iodide or sodium chloride (seetable below) were processed in a ceramic ball mill (see Example 15)using 100 micron yttria stabilized zirconia grinding media at a millspeed of 4200 RPM and recirculation pump speed of 600 RPM for 1000minutes. Sample was also made without any sodium iodide but with PVP(sample C). Particle size was measured of the as prepared dispersions bydynamic light scattering. Particle size was also measured for thedispersions after being dried under reduced pressure and redispersed inwater by dynamic light scattering. Also to be noted that addition ofsoluble iodide salt (as sodium iodide) along with PVP helped indecreasing the particle size of CuI more efficiently, and further, suchdispersions were highly stable.

TABLE 32 Average particle Average PVP Size particle Size Sample CuISalt, K17 (as (dried and ID (g) (g) (g) Water prepared) redispersed)Remarks A 1.101 NaI, 45 200 mL 5 nm 5 nm Clear green 0.399 dispersion B1.101 NaCl, 45 200 mL >1 micron >1 micron Hazy yellow 0.399 dispersion,Large amount of sediment C 1.101 None, 45 200 mL >1 micron >1 micronHazy yellow 0.000 dispersion, Large amount of sediment

In another experiment the benefits seen by adding soluble iodide werereevaluated by lowering its concentration relative to the CuI used. Inaddition, relative amount of PVP was also decreased. 200 mL deionizedwater with 1.0 g PVP 10K, 4.0 g copper iodide, and 0.1 g of sodiumiodide were processed in a ceramic ball mill (see Example 15) using 100micron yttria stabilized zirconia grinding media at a mill speed of 4200RPM and recirculation pump speed of 600 RPM for 250 minutes. Particlesize was measured of the as prepared dispersion by dynamic lightscattering to be 10-80 nm. Particle size was also measured for thedispersion after being dried under reduced pressure and redispersed inwater by dynamic light scattering to be 10-80 nm. Both the as preparedand dried and redispersed dispersions exhibit a much stronger resistanceto settling than similar preparations without the addition of sodiumiodide.

Example 55 Efficacy in CuI Containing Wound Dressings by Addition ofAcids and Salts

In this example the CuI/PVP samples were made using PVP with a molecularweight of 10,000 and along with sodium iodide and was prepared asdetailed in Example 53, Sample A.

-   -   a) To a round bottom flask was added 0.2 g Citric Acid (Citric        acid >99%, Aldrich C0759), 1 g of prepared CuI/PVP 10 k powder        (2.38 wt % CuI) and 5 mL DI-water.    -   b) a) To a round bottom flask was added 0.2 g Citric Acid        (Citric acid >99%, Aldrich C0759), 1 g of PVP 10K powder and 5        mL DI-water.    -   c) To a round bottom flask was added 0.2 g Ascorbic Acid        (L-Ascorbic acid >99%, Aldrich 95210), 1 g of prepared CuI/PVP        10K powder (2.38 wt % CuI) and 5 mL DI-water.    -   d) a) To a round bottom flask was added 0.2 g Ascorbic Acid        (L-Ascorbic acid >99%, Aldrich 95210), 1 g of PVP 10K powder and        5 mL DI-water.    -   e) To a round bottom flask was added 0.2 g Citric Acid (Citric        acid >99%, Aldrich C0759), 0.1 g Sodium Bicarbonate, and 5 mL        DI-water. This was allowed to react to form a citrate salt and        form a clear solution with a pH of 4. Then 1 g of prepared        CuI/PVP 10 k powder (2.38 wt % CuI) was added.    -   f) To a round bottom flask was added 0.2 g Ascorbic Acid        (L-Ascorbic acid >99%, Aldrich 95210), 0.1 g Sodium Bicarbonate,        and 5 mL DI-water. This was allowed to react to form a citrate        salt and form a clear solution with a pH of 4. Then 1 g of        prepared CuI/PVP 10 k powder (2.38 wt % CuI) was added.

These aqueous dispersions were used to form wound dressing as in Example33c. E. coli (ATCC #25922) was used instead of P. aeruginosa to test theantimicrobial properties. These were tested by culturing a single colonyof E. coli (ATCC #25922) overnight to stationary phase in tryptic soybroth (TSB). The following day, the culture was diluted in TSB to readoptical density in a Synergy 2 reader (from Biotek Instruments Inc,Winooski, Vt.). Following this, 0.25 ml of culture was plated onto petridishes containing tryptic soy agar (TSA). 10 mm circular pieces of gauzesamples were then placed onto inoculated plates. Each piece of gauze waslightly pressed to ensure contact with the agar and then the plate wasinverted and incubated at 37° C. for 16-24 hours. After this timeperiod, a zone of inhibition (ZOI) was observed around the wounddressings which was optically clear (not hazy) showing that no bacteriagrew in this zone. The size of this zone (zone of inhibition) was notedin mm from the perimeter of the wound dressings after 24 hours. The zoneof inhibition around sample (a) was 5.0 mm, (b) 2.5 mm, (c) 3.0 mm, (d)0.5 mm, (e) 5 mm, (f) 3 mm.

Example 56 Efficacy in CuI Containing Wound Dressings by Addition ofCitrate Salt at Different Concentrations

In this example the CuI/SLS powder used was 75/25 by weight and wasproduced by grinding as described in Example 28.

-   -   (a) To a round bottom flask was added 0.2 g Citric Acid (Citric        acid >99%, Aldrich C0759), 0.0875 g Sodium Bicarbonate        (Aldrich 56014) and 5 g DI-water. The mole ratio of citric acid        to sodium bicarbonate was 1. This was allowed to react and form        a clear solution with a pH of 3.5. To this solution was added 1        g of PVP 10K and 0.3 g of prepared CuI/SLS powder (25% Cu). The        pH remained constant and a blue or green color developed.    -   (b) A sample was prepared as in example (a) with an increased        amount of sodium bicarbonate. The amount of sodium bicarbonate        used was 0.175 g. The mole ratio of citric acid to sodium        bicarbonate was 2. The pH was 5.5. All other parameters remained        as in example (a).    -   (c) A sample was prepared as in example (a) with an increased        amount of sodium bicarbonate. The amount of sodium bicarbonate        used was 0.263 g. The mole ratio of citric acid to sodium        bicarbonate was 3. The pH was 7. All other parameters remained        as in example (a).    -   (d) To a round bottom flask was added 0.2 g Citric Acid (Citric        acid >99%, Aldrich C0759), 0.263 g Sodium Bicarbonate (Aldrich        S6014) and 5 g DI-water. The mole ratio of citric acid to sodium        bicarbonate was 3. This was allowed to react and form a clear        solution with a pH of 7. To this solution was added 1.225 g of        PVP 10K and 0.075 g of SLS powder.        These aqueous dispersions were used to form wound dressing and        tested as in Example 55 and tested against E. coli (ATCC        #25922). The zone of inhibition around sample (c) was larger        than (a) and (b). The zone of inhibition around sample (b) was        larger than (a). Sample (d) showed no zone of inhibition. After        testing it was observed that sample (c) had a stronger blue        color, followed by samples (b) and (a).

Example 57 Improved Dispersibility of CuI by Milling with Soluble Saltsand Polymer, and Use of Metals

a) Copper iodide, sodium iodide, polyvinvylpyrrolidone K17, anddeionized water were combined as described in the table below. Thesematerials were processed together in a ceramic ball mill (see Example15) using 100 micron grinding media (3M™ Micro Milling Media ZGC) at amill speed of 4200 RPM and recirculation pump speed of 600 RPM.

TABLE 33 CuI (g) PVP (g) NaI (g) DI-Water (mL) Grinding Time (min) 9 401 150 1000 9 2 1 200 350 9 2 0.25 200 1200 9 0.9 0.1 200 450 9 0.95 0.05200 350 18 1.95 0.05 200 1000 90 9 1 140 350 90 9.5 0.5 200 1330

Each milled product appeared as a semi translucent opalescent dispersionthat was stable against settling with particle sizes around 10-30 nm.The dispersions were dried to form purple colored solids under reducedpressure. Subsequent redispersal formed dispersions similar to as beforedrying with particle sizes around 10-30 nm.

b) 18 g Copper iodide, 0.05 g sodium iodide, 1.95 g copovidone VA64(copolymer of polyvinvylpyrrolidone and vinvyl acetate), and 200 mLdeionized water were combined and processed together in a ceramic ballmill (see Example 15) using 100 micron grinding media (3M™ Micro MillingMedia ZGC) at a mill speed of 4200 RPM and recirculation pump speed of600 RPM for 350 minutes.

This milled mixture appeared as a semi translucent opalescentdispersion. This dispersion was dried to a solid under reduced pressuredand subsequently redispersed to form a similar dispersion as beforedrying with a particle size around 10-30 nm.

c) 9 g Copper iodide, polyvinvylpyrrolidone 0.9 g PVP K17, 0.1 g silvernitrate, and deionized water were combined and processed together in aceramic ball mill (see Example 15) using 100 micron grinding media (3M™Micro Milling Media ZGC) at a mill speed of 4200 RPM and recirculationpump speed of 600 RPM for 400 minutes. A translucent dispersion wasformed after processing.

d) 9 g of copper iodide and 0.9 g PVP K17 were processed as in (c) using0.1 g copper(I) acetate rather than silver nitrate. A translucentdispersion was formed after processing.

e) 9 g of copper iodide and 0.9 g PVP K17 were processed as in (c) using0.1 g elemental silver (10 micron powder) rather than silver nitrate. Atranslucent dispersion was formed after processing.

f) 9 g of copper iodide and 0.9 g PVP K17 were processed as in (c) using0.1 g elemental copper (10 micron powder) rather than silver nitrate. Atranslucent dispersion was formed after processing.

g) 9 g of copper iodide and 0.9 g PVP K17 were processed as in (c) using0.1 g elemental zinc (10 micron powder) rather than silver nitrate. Atranslucent dispersion was formed after processing.

h) 9 g of copper iodide and 0.9 g PVP K17 were processed as in (c) using0.1 g elemental iodine rather than silver nitrate. A translucentdispersion was formed after processing.

Example 58 Improved Dispersibility of AgI by Milling with Soluble Iodideand Polymer

a) 9 g Silver iodide, 0.1 g potassium iodide, 0.9 g polyvinylpyrrolidoneK17, and 200 mL deionized water were combined and processed together ina ceramic ball mill using 100 micron grinding media (3M™ Micro MillingMedia ZGC) at a mill speed of 4200 RPM and recirculation pump speed of600 RPM for 350 minutes.

This milled mixture appeared as a semi translucent green dispersion.This dispersion was dried to a solid under reduced pressured andsubsequently redispersed to form a similar dispersion as before dryingwith a particle size around 10-30 nm.

Example 59 Wound Dressing Compositions

a) To a round bottom flask was added 10 g trisodium citrate (Aldrich),6.67 g of copper iodide powder as prepared in example 88 as 90% CuI, 9%PVP, and 1% NaI, 83.33 g PVP K17, and 300 mL deionized water. Thisaqueous dispersion had 25% solids and was used to form wound dressing byapplying 1 g of liquid dropwise to a 2×2 inch cellulose polyester fabricand drying the fabric in an oven at 75° C. on a glass tray.

b) Similar wound dressings were prepared with 6.67 g of copper iodidepowder as prepared in example 89 as 90% CuI, 9% PVP, and 1% NaI, 93.33 gPVP K17, and 300 mL deionized water.

c) Standard wound dressings were similarly prepared and consisted of 10%trisodium citrate and 90% PVP K17.

d) These wound dressings were tested by applying a 10 mm circular swatchto a bacterial pseudomonas aeruginosa (ATCC #9027) biofilm, such thatthe biofilm was completely covered by the wound dressing. The biofilmhad been grown overnight on a 0.2 micron membrane on agar andtransferred to fresh agar upon application of the wound dressing.Bacterial reductions were determined by removing the wound dressing,sonicating the membranes in PBS, and plating the PBS at 10× dilutions tocount viable colony forming units.

e) In biofilm testing described above the samples containing both copperiodide and trisodium citrate (sample a) performed superior to sampleswithout citrate and without both citrate and copper iodide (sample b andc).

Example 60 Preparation and Testing of Wound Dressings

a) Preparation of Wound Dressings

i) Wound dressings were prepared by combining 0.0667 g copper iodidepowder as described in Example 57a (90% CuI, 1% NaI, 9% PVPK17), 1.733 gPVP K17, 0.20 g trisodium citrate, and 6 mL deionized water. Thisdispersion was applied to a 4 sq in piece of gauze as in Example 55 at0.25 g solids per 4 sq in. This was subsequently dried and furtherprocessed to form wound dressings as described in Example 55.ii) 0.0667 g copper iodide powder as described in Example 57c (90% CuI,1% AgNO₃, 9% PVPK17), 1.733 g PVP K17, 0.20 g trisodium citrate, and 6mL deionized water were mixed to form wound dressings as in (i).iii) 0.0667 g copper iodide powder as described in Example 57a (90% CuI,1% NaI, 9% PVPK17), 1.333 g PVP K17, 0.20 g trisodium citrate, 0.40 gascorbic acid, and 6 mL deionized water were mixed form wound dressingsas in (i).iv) 1.733 g PVP K17, 0.20 g trisodium citrate, and 6 mL deionized watermixed to form wound dressings as in (a).

b) Testing of Wound Dressings

Wound dressings (i-iv) were tested as described in Example 55 usingPseudomonas aeruginosa (ATCC #9027), Staphylococcus aureus (ATCC #25923,and Escherichia coli (ATCC #25922). Unless mentioned otherwise onlythese bacterial strains were used to test the wound dressings in otherexamples.

The zone of inhibition (ZOI) for (i) and (ii) were equivalent for allthree micobes. The ZOI for (iii) was larger than both (i) and (ii) forall three microbes. There was no ZOI for (iv) for Pseudomonas aeruginosaand Escherichia coli, however, there was a ZOI smaller than (i) or (ii)against Staphylococcus aureus.

Example 61 Preparation and Testing of Wound Dressings

a) Preparation of Copper Iodide Wound Dressing

0.133 g copper iodide powder as described in Example 57a (90% CuI, 1%NaI, 9% PVPK17), 1.266 g PVP K17, 0.20 g trisodium citrate, 0.40 gascorbic acid, and 6 mL deionized water were mixed form wound dressingsas in Example 33c. The loading of solids was at 0.50 g per 4 sq in.

b) Preparation of Control Wound Dressing

1.333 g PVP K17, 0.20 g trisodium citrate, 0.40 g ascorbic acid, and 6mL deionized water mixed to form wound dressings as in Example 33c. Theloading of solids was at 0.50 g per 4 sq in. This sample had no copper.

c) Testing of Wound Dressings

Copper iodide and Standard wound dressings were tested along withAquacel Ag (silver containing commercial wound dressing) as described inExample 55 using Pseudomonas aeruginosa (ATCC #9027), Staphylococcusaureus (ATCC #25923), and Escherichia coli (ATCC #15597). Zone ofinhibition results are described in the table below.

TABLE 34 Plate # Organism Sample ZOI (mm) 1 Psudomonas aeruginosaControl 0.0 (ATCC# 9027) Aquacel Ag 1.6 2 Psudomonas aeruginosa CuI 1.6(ATCC# 9027) Aquacel Ag 1.6 3 Staphylococcus aureus CuI 1.6 (ATCC#25923) Aquacel Ag 1.6 4 Escherichia coli CuI 1.6 (ATCC# 15597) AquacelAg 1.6

Example 62 Wound Dressings Prepared with Alternative Polymers

0.133 g copper iodide powder as described in Example 57a (90% CuI, 1%NaI, 9% PVPK17), 1.266 g of polymer as described in the table below,0.20 g trisodium citrate, 0.40 g ascorbic acid, and 6 mL deionized waterwere mixed form wound dressings as in (a) at 0.75 g per 4 sq inch. Thesewound dressings were tested against Pseudomonas aeruginosa (ATCC #9027)as described in Example 55. All samples had equivalent zones ofinhibition as described in the table below.

TABLE 35 Polymer Zone of Inhibition (mm) PVP K17 1.5 PVP MW = 55,000 1.5VA64 Copolymer 1.5 80% PVP K17, 20% Carboxymethylcellulose 1.5 PEG MW =8,000 1.5 None 1.5

Example 63 Wound Creams

a) Antimicrobial wound creams were prepared by sodiumcarboxymethycellulose, trisodium citrate, and copper iodide powder asprepared in Example 57a as 90% CuI, 9% PVP, and 1% NaI. These creamswere prepared at 6% sodium carboxymethycellulose, 10% trisodium citrate,and copper levels of 0.00%, 0.25%, 0.50%, 1.00%, and 5.00%.

b) These wound creams were tested using a zone of inhibition method. A 6mm well was formed in the center of an inoculated agar plate and filledwith the wound cream. Each cream was run in triplicate on three separateplates. Each plate was allowed to incubate overnight at 37° C. and thenthe zone of inhibition was measured. Each cream was tested againstPseudomonas aeruginosa ATCC #9027) and Staphylococcus aureus (ATCC#25923).

c) The zone of inhibition measured results of wound creams described in(a) along with commericial bacitracin ointment tested as in (b). Thesemeasurements are in cm for the diameter of the zone of inhibitionincluding the well.

TABLE 36 0.00% Cu 0.25% Cu 0.50% Cu 1.00% Cu 5.00% Cu Bacitracin P.aeruginosa 1.0 ± 0.3 1.2 ± 0.2 1.1 ± 0.0 1.4 ± 0.2 2.1 ± 0.0 0.6 ± 0.1S. aureus 1.5 ± 0.1 1.6 ± 0.1 1.8 ± 0.1 2.2 ± 0.2 4.4 ± 0.4 0.6 ± 0.1

Example 64 Functionalization of CuI with SiO₂

To a one liter flask was added 200 mL deionized water (18 mΩ-cm) with pHadjusted to 2.0 using dilute HCl and 10.0 g (0.05251 m) of cuprousiodide. The mixture was stirred using a high shear mixer (Ross LSKMixer) at a maximum speed of 20,000 rpm. While mixing at 15,000 rpm 4.75g (0.228 m) of tetraethylorthosilicate (Aldrich, 99%) was addeddropwise. This resulted in a fine white dispersion. This mixture wasprocessed in a ceramic ball mill (see example 15) using 100 microngrinding media (3M™ Micro Milling Media ZGC) at a mill speed of 4200 RPMand recirculation pump speed of 600 RPM for 1300 minutes. After 4 hoursof milling the pH had increased to 4.0, after 6 hours of milling the pHhad increased to 5.6, and after completion of milling (1300 min) the pHhad increased to 6.3. The dispersion had developed an opaque whiteappearance with pink foam.

This dispersion was then removed from the mill and placed under highspeed stirring at 3000 rpm; 0.2 mL of dilute ammonia (3 ml of 28%ammonia solution in 25 ml of deionized water) was added and allowed tomix for 1 hour. The pH initially went basic and then decreased to asteady value of 6.0. This dispersion was heated to reflux under magneticstirring for 2 hours cooled to room temperature and left stirringovernight.

This dispersion was filtered on a 0.8 micron nylon filter (Osmonics) andwashed with excess water and ethanol. The filtrate was clear and withoutcolor. The dry product was cured in a convection oven at 200° C.overnight to give an off white fine powder of composition 12 wt % SiO₂and 88 wt % CuI. This powder was dispersed in water and its efficacytested against P. aeruginosa (ATCC #9027) at a copper concentration of60 ppm. Table 37 shows the results after 15 minutes compared to the PBScontrol. The starting bacterial titer concentration was 2.4×10⁶ cfu/ml.

TABLE 37 Time PBS Control CuI/SiO2 15 min 0.07 ± 0.03 3.73 ± 0.07

The CuI/SiO₂ powder was added to Harmony White Paint (Sherwin WilliamsInterior Acrylic Latex semi gloss “green sure designation”) at a copperconcentration of 0.1 wt % stirred and stored for six days and the colorcoordinates (CIE 1931 color space) determined as shown below in theTable below.

TABLE 38 Liquid Paint color properties with and without CuI/SiO₂ CIEColor Coordinates Sample Storage time L* a* b* Harmony White PaintLiquid Initial 88.43 −0.93 2.60 Harmony White Paint Liquid Six days88.39 −0.93 2.57 Harmony Paint Liquid with Initial 87.77 −2.30 3.86 0.1wt % Cu Harmony Paint Liquid with Six days 87.16 −2.59 3.60 0.1 wt % Cu

The paint with and without CuI/SiO₂ as described in the above table wasapplied to a 2″×2″ aluminum substrate and cured at 85° C. The colorcoordinates were determined for the painted substrates initially andafter storage at 85° C. for six days. The results are listed below inthe table.

TABLE 39 Cured paint on aluminum substrate with and without CuI/SiO₂added CIE Color Coordinates Sample Storage time L* a* b* Harmony WhitePaint Liquid Initial 93.98 −0.84 1.80 Harmony White Paint Liquid Sixdays at 94.44 −1.31 3.63 85° C. Harmony Paint Liquid with Initial 93.31−2.96 4.61 0.1 wt % Cu Harmony Paint Liquid with Six days at 92.01 −2.817.03 0.1 wt % Cu 85° C.

Example 65 Silica Functionalized Copper Iodide

a) 200 mL deionized water (18 mΩ-cm) with pH adjusted to 2.0 usingAcetic Acid and 10.0 g (0.05251 m) of cuprous iodide were processed in aceramic ball mill (see Example 15) using 100 micron grinding media (3M™Micro Milling Media ZGC) at a mill speed of 4200 RPM and recirculationpump speed of 600 RPM for 350 minutes. 4.75 g (0.228 m) oftetraethylorthosilicate (Aldrich, 99%) was added and milling wascontinued for another 10 minutes.

This dispersion was then removed from the mill and placed under highspeed stirring at 3000 rpm; 0.2 mL of dilute sodium hydroxide was addedand allowed to mix for 1 hour. This dispersion was heated to refluxunder magnetic stirring for 1 hour and then cooled to room temperatureand left stirring overnight.

This dispersion was filtered on a 0.8 micron nylon filter (Osmonics) andwashed with excess water and ethanol. The filtrate was clear and withoutcolor. The dry product was cured in a convection oven at 120° C.overnight to give an off white fine powder of composition 12 wt % SiO₂and 88 wt % CuI.

b) Another formulation was processed where 10.0 g of Copper iodide and4.75 g of tetraethylorthosilicate were milled as in (a) using ethanolrather than deionized water. This dispersion was dried under reducedpressure at room temperature to give a fine powder. All of the othersteps were similar.

c) Copper iodide was processed as in (b), where ammonia was used ratherthan sodium hydroxide.

Example 66 Disinfectant with Acids

Disinfectant solutions D1, D3 and D5 were respectively prepared indeionized water with 5% of ascorbic acid, 5% nitric acid and 5% citricacid as shown in the table below. In addition three additionalformulations D2, D4 and D6 were also prepared with these respectiveacids along with CuI particles functionalized with sodium lauryl sulfate(SLS) to yield a final copper concentration of 60 ppm in theseformulations. These were prepared by stirring the components for onehour in sure seal bottles. All of the samples with CuI/SLS were slightlyhazy.

TABLE 40 Ingredient Formulations (g) D1 D2 D3 D4 D5 D6 D7 D8 Water 50 5050 50 47.5 50 Ascorbic 2.63 2.63 acid Citric acid 2.63 2.63 Acetic acid2.5 2.5 CuI/SLS 0.0126 0.0126 0.0126 Ascorbic acid (>99%, Fluka, UnitedKingdom) Citric acid, 99% (Sigma-Aldrich Corp., St. Louis, MO) Aceticacid, ≧99.7% (Sigma-Aldrich Corp., St. Louis, MO) CuI/SLS (75/25% byweight prepared as in Example 62)

The pH of both of the acetic acid containing formulation was measuredand found to be 2.383 for D5 and 2.346 for D6. This was done using anOrion 290A+pH meter equipped with an Orion Ross Sure-flow GlassCombination pH Electrode. The pH meter was calibrated with pH standards4, 7 and 10 (all pH standards from ACROS Organics, Geel, Belgium) togive a slope of 98.5.

All of the solutions above were analyzed for their antimicrobialproperties by testing them against Staph aureus. A hard surface tile(10.8×10.8 cm) was inoculated with 10⁹ CFU Staph aureus and spread overthe surface. After drying this tile was sprayed with the test solutionto cover the tile completely (˜2 ml) and was swabbed after a period oftwo minutes, and the swab was dropped in a DE neutralizing solutiondiluted 100 times with PBS buffer to ensure that the acidity of thespray solution did not change the pH of the neutralizing solution. Thesesolutions were then cultured on agar plates as described earlier. Theresults are seen in the Table below.

TABLE 41 Testing Results against S. aureus (2 minutes of contact time)Testing against S. aureus ATCC 25923 5% 5% ascorbic ascorbic 5% citric5% citric 5% acetic 5% acetic acid acid + acid acid + acid acid + PBSsolution CuI/SLS solution CuI/SLS solution CuI/SLS Control (D1) (D2)(D3) (D4) (D5)* (D6)* Log₁₀ Log₁₀ Log₁₀ Log₁₀ Log₁₀ Log₁₀ Log₁₀Reduction Reduction Reduction Reduction Reduction Reduction Reduction0.08 ± 0.07 0.65 ± 0.11 1.05 ± 0.14 0.65 ± 0.08 1.78 ± 0.19 0.91 ± 0.131.68 ± 0.14 Original titer = 6.80E+07 cfu/mL *These tests were doneseparately, the PBS standards for this series read −0.24 ± 0.12

Example 67 Disinfectant with Chitosan

A water based disinfectant solution was prepared with 8% of acetic acid,60 ppm Cu, 3% Isopropanol and 3400 ppm Chitosan as follows:

In a sure seal bottle equipped with a stir bar, 0.0131 g of copper (I)iodide (75%)/sodium lauryl sulfate (25%) powder, prepared in Example 28,was mixed with 0.186 g chitosan (Sigma-Aldrich Corp., St. Louis, Mo.),1.65 g isopropanol, 99.5% (Sigma-Aldrich Corp., St. Louis, Mo.) and48.35 g deionized water. Lastly, 4.4 g acetic acid, ≧99.7%(Sigma-Aldrich Corp., St. Louis, Mo.) was added. This solution wasstirred at room temperature for one hour to give a translucent, slightlyhazy, colorless solution. The pH of this solution was found to be 2.534using an Orion 290A+pH meter equipped with an Orion Ross Sure-flow GlassCombination pH Electrode. The pH meter was calibrated with pH standards4, 7 and 10 (all pH standards from ACROS Organics, Geel, Belgium) togive a slope of 97.9. This solution was also then sent for 2 minutecontact testing against staph aureus as in Example 66. The resultsshowed that Log₁₀ reduction for the sample in two minutes was >4.25±0.00and for the PBS buffer the result was 0.53±0.38. The original titerbacterial concentration was 8.85E+06 cfu/mL.

Example 68 Pet Chews

The pet chews examined here were Dentley's Natural Flavor Pig Ears,Prime Cuts for Medium Dogs. They are made in the USA and are distributedby Pacific Coast Distributing, Inc. in Phoenix, Ariz.

These ears were cut into pieces about 6 to 7 sq cm in size. Some ofthese pieces delaminated on cutting. The experiments reported below wereonly done on non-delaminated samples.

Each pig ear piece was first weighed and then soaked with stirring inliquid medium of choice for a specific amount of time at roomtemperature. The pig ear pieces were then removed from the medium, wereblotted dry with a kim-wipe and were weighed so the % weight increasecould be monitored.

The pieces were first evaluated for ethanol soak for various periods oftime and the average weight gain was 0.1% after a soak period of onehour. We used this soak to kill any bacteria on the surface of thesepieces. This was then followed by a water soak (deionized water) forvarious periods of time and found out that it absorbed about 43% ofwater in a period of 90 minutes. We also tested some pieces which weredirectly soaked in water (without ethanol soak) and the weight gain waswithin one percent of the above value. Ethanol was obtained fromPharmco-Aaper, Brookfield, Conn.

In order to treat the pig ear pieces with functionalized CuI particles,we adopted one hour soak in ethanol followed by a 90 minute soak inwater comprising functionalized CuI particles. After the ethanol soakthe samples were wiped dry and left for about 15 minutes at roomtemperature for further drying. After the water soak, the samples werewiped and dried at 85° C. for 90 minutes. The amount of CuI uptake wasestimated from the concentration of the CuI in water and the calculatedwater uptake (43%) from the above experiments.

The CuI functionalized with PVP and NaI was used as prepared in Example57a (CuI/PVP/NaI weight ratio was 90/9/1). When the soaking solution had116.4 ppm of CuI, then it resulted in imparting 0.005% of CuI by weightto the pig ear. When the concentration of CuI was doubled, thecalculated copper intake increased proportionately. The pig ear after itabsorbed 0.005% CuI did not look different from the original pig ear. At0.01% CuI uptake to about 0.2% uptake, the pig ear looked unchangedexcept that a slight green color was seen at the edges of these pieces.

Example 69 Body Cleaner (Shampoo) Include Color Change and EfficacyResults

A solution of body cleaner was prepared by combining 85.5 g Steol 4N(Stepan Company, Northfield, Ill.) with 29.04 g Amphosol HCG (StepanCompany, Northfield, Ill.) and 185.46 g deionized water in a glassbottle equipped with a stir bar. The solution was stirred for one hourat room temperature to give a clear, colorless, foamy solution.

After preparing the above body cleaner, the other ingredients were addedand stirred for additional three hours at room temperature. Theproportion of these is shown below. Each of these formulations wereprepared with had 60 ppm copper concentration. Sodium citrate tribasichydrate, ≧99% was obtained from Sigma-Aldrich Corp., St. Louis, Mo.CuI/SDS was 75/25 in weight proportion and made as in Example 28.CuI/Silica was 88% CuI and 12% silica made as in Example 64, andCuI/PVP/NaI was in 90/9/1% in weight proportion and made as in Example57a.

TABLE 42 Formulation Ingredients (g) F1 F2 F3 De-ionized water 61.82Steol 4N 28.5 Amphosol HCG 9.68 Sodium citrate 0.03 0.03 0.03 CuI/SLS0.0241 CuI/Silica 0.0205 CuI/PVP/NaI 0.02

Antimicrobial testing results after 24 hours are shown below in thetable below. In these tables the original titer for P. aeruginosa (ATCC#9027) was 3.43E+07 cfu/mL, and for S. aureus (ATCC #25923) 1.11E+07cfu/mL.

TABLE 43 Solution Without CuI F1 F2 F3 Log₁₀ Log₁₀ Log₁₀ Log₁₀ MicrobeReduction Reduction Reduction Reduction P. aeruginosa 1.53 ± 0.09 5.31 ±0.16 5.76 ± 0.67 5.58 ± 0.07 S. aureus 1.39 ± 0.05 3.32 ± 0.03 3.27 ±0.06 3.35 ± 0.30

Example 70 Solvent Based Nail Polish

A solution of 0.05% Cu in the dried coating was prepared by mixing0.0014 g CuI functionalized with silica powder (88% CuI and 12% byweight as prepared in Example 64) with 4 g Orly Bonder Rubberized nailpolish Basecoat (orange color, available from in Orly International Inc,Los Angeles, Calif.)) in a small glass vial equipped with a stir bar.Orly bonder is a solvent based nail polish base and comprises of butylacetate, isopropyl alcohol, heptane, ethyl acetate, trimethyl pentanyldiisobutyrate, tosylamide/epoxy resin, polyvinyl butyral,nitrocellulose, benzophenone-1, red 17, violet 2, yellow11 and upondrying at room temperature has a solid content of 20.3%. This solutionwas stirred at room temperature for 1 hour and was sonicated for 1 hour.It was then left to stir overnight at room temperature. The resultingsolution is slightly hazy and orange in color. No precipitate is seenwhen sitting for several hours at room temperature. The coatings withand without the CuI/silica powder could not be distinguished by eye.

Functionalized CuI particles were made as described in Example 54(SampleA), excepting that instead of PVP a PVP-olefin copolymer Ganex® V516 wasused and the grinding medium was isopropanol. The composition by weightwas CuI90%/9% V516 copolymer/1% NaI. This material was also compatiblewith solvent based Orly Bonder Rubberized nail polish Basecoat.

Example 71 Testing of Antimicrobial Properties Against Mycobacteriumsmegmatis, Mycobacterium fortuitum and Candida albicans (Yeast)

a) Copper iodide powder was prepared as in Example 28 as 75% copperiodide and 25% sodium lauryl sulfate.

b) Copper iodide powder was prepared as in example 57a as 90% copperiodide, 9.75% polyvinylpyrrolidone, 0.25% sodium iodide.

c) Copper iodide powders as described in (a) and (b) were tested againstthe yeast Candida albicans (ATCC #10231), Mycobacterium smegmatis (ATCC#14468) and M. fortuitum (ATCC #6841) at 60 ppm Cu. Log₁₀ reductions incolony forming units are shown in the tables below (“>” indicates noviable colony forming units). Both M. fortuitum and M. smegmatis wereharvested after 48 hours of growth before subjecting them to theantimicrobial testing.

TABLE 44 Log₁₀ Reductions against C. albicans Time PBS Control CuI/SLSCuI/PVP/NaI 1 min —  0.11 ± 0.04 0.05 ± 0.03 5 min —  3.21 ± 0.44 0.51 ±0.03 15 min 0.02 ± 0.04  4.12 ± 0.00 2.75 ± 0.05 1 hour −0.01 ±0.11  >4.12 ± 0.00 >3.89 ± 0.34  6 hour 0.11 ± 0.16 >4.12 ± 0.00 3.74 ±0.12 24 hour 0.14 ± 0.08 >4.12 ± 0.00 >4.12 ± 0.00  48 hour 0.30 ±0.13 >4.12 ± 0.00 >4.12 ± 0.00  Original titer = 6.65E+5 cfu/ml

TABLE 45 Log₁₀ Reductions against M. fortuitum Time PBS Control CuI/SLSCuI/PVP/NaI 15 min 0.03 ± 0.02 0.00 0.69 ± 0.03 1 hour 0.06 ± 0.11 1.81± 0.04 1.76 ± 0.01 24 hour 0.30 ± 0.30 4.24 ± 0.13 4.05 ± 0.20 Originaltiter = 1.40E+7 cfu/ml

TABLE 46 Log₁₀ Reductions of against M. smegmatis Time PBS ControlCuI/SLS CuI/PVP/NaI 15 min 0.03 ± 0.02 0.00 2.61 ± 0.01 1 hour −0.14 ±0.13   2.46 ± 0.54 4.40 ± 0.36 24 hour 0.63 ± 0.27 >5.35 ± 0.00 >5.35 ±0.00  Original titer = 1.12E+7 cfu/ml

These results on M. smegmatis and M. fortuitum suggest that the presentfunctionalized particles would also be effective against M.tuberculosis, and even against the strains of M. tuberculosis which areresistant to conventional antibiotics—since the mechanism ofantimicrobial activity of the present antimicrobial agents is verydifferent from the antimicrobial mechanisms of conventional antibiotics.Similarly, the results on C. albicans show the potential of thesematerials to control yeast infections.

Example 72 Antimicrobial Efficacy of an Aqueous Acrylic Indoor Paint

The CuI/SLS powder (as prepared in Example 28 with a weight proportionof 75:25 of CuI and SLS), an antimicrobial (AM) additive was added toHarmony White Paint (Sherwin Williams (Cleveland, Ohio) Interior AcrylicLatex semi gloss “green sure designation”) at a copper concentration of0.1 wt % and at 0.25% wt. and stirred into the paint. The a* and b*color coordinates of the dry paint were measured after applying to thealuminum substrates and waiting for one week and these for the paintwithout and with (0.1% Cu) antimicrobial additive were −0.9, 1.3 and−4.6, 5.9 respectively. The antimicrobial properties of these coatingswere measured after exposing these coatings to growth culture asdescribed earlier for 6 hours to P. aeruginosa. The results (Log₁₀reduction) are in the table below.

TABLE 47 Paint without Paint with Paint with Time AM additive 0.1% Cu0.25% Cu 6 hours 1.05 ± 0.15 >6.06 ± 0.00 >6.06 ± 0.00 Original Titer =5.77E+06 cfu/mL

Example 73 Preparation of Polyurethane Foam with Copper Iodide

a) Preparation of Copper Iodide Dispersion for PolyurethaneIncorporation: Block copolymer functionalized copper iodide was preparedas in Example 45 as 90.9% CuI and 9.1% DisperBYK-190® in the solids.Water was exchanged with 1,4-butanediol by addition of 1,4-butanedioland removal of water under reduced pressure. The resultant dispersion in1,4-Butanediol was at 38.96% solids as measured by thermogravimetricanalysis.

b) Preparation of Standard Polyurethane Foam: FlexFoam-iT!® 25(Smooth-On, Inc. Easton, Pa.) was prepared by thoroughly mixing 1 part A(isocyanate component) and 2 parts B by weight. This was cast in aplastic dish to give an off-white foam.

c) Preparation of Antimicrobial Polyurethane Foam: 10 g of Part B ofFlexFoam-iT!® 25 (from Smooth-On, Inc. Easton, Pa.) was mixed thoroughlywith 0.66 g CuI/1,4-butanediol dispersion described in (a). This wasthen thoroughly mixed with 5 g Part A (isocyanate component). This wascast in a plastic dish to give an off-white foam that was similar to thestandard foam described in (b).

Example 74 Antimicrobial Epoxy Coating

EPON SU-3 (Miller-Stephenson Chemical Company INC, Danbury, Conn.) andEPALLOY 9000 (CVC Thermoset Specialists Maple Shade, N.J.) were heatedseparately to 60° C. and while at temperature mixed to form a clearyellow resin. To this mixture was added the anhydride(4-Methylhexahydrophthalic anhydride obtained from BroadviewTechnologies INC. Newark, N.J.) and mixed well to form an opaque resin.To this mixture was added the CuI adduct and again mix well. Theantimicrobial CuI functionalized particles were prepared by grinding inthe following proportion—49.4% CuI, 49.5% Ganex WP—660(polyvinylpyrrolidone with olefin or alkylated groups obtained fromAshland (New Milford, Conn.)), 1% NaI in isopropanol. After grinding,isopropanol was removed and the resulting powder was added to the resin.The CuI formulated powder dispersed very well in the epoxy medium togive a smooth free flowing resin. The curing agent (AJICURE MY-H anamine adduct obtained from AJINOMOTO CO., INC Japan) was then added andthe mixture thoroughly mixed to give a red colored resin. This wasdegassed under vacuum at 25° C. until no bubbles were seen. The epoxyformulation was then brush coated onto cleaned aluminum substrates andpre-cured under ambient atmosphere at 85° C. for 30 minutes and completecure at 150° C. for 45 minutes. Copper content in the final coatings was0.1 weight % (based on 100% solids). The antimicrobial efficacy of thecoatings was evaluated using JIS2801-2000 after exposing the microbe tothe coating for a period of 24 hours. Coatings without antimicrobialadditive were compared, and as shown below, the coatings with theadditive were far superior in reducing the microbial population.

TABLE 48 Log10 reduction of P. aeruginosa Log10 reduction of S. aureus(ATCC # 9027) (ATCC # 25923) Without With Without With antimicrobialantimicrobial antimicrobial antimicrobial additive additive additiveadditive −0.34 ± 0.14 >3.61 ± 0.56 0.31 ± 0.04 >4.44 ± 0.00

Example 75 Activity of CuI Particles Against Sulfate Reducing Bacteria(SRB)

The purpose of this experiment was to determine if copper (I) iodideparticles could act as a bacteriocidal agent against Desulfovibriovulgaris (ATCC 29579), an anaerobic sulfate reducing bacteria (SRB). TheCuI particles were made as in Example 57a (CuI/PVP/NaI weight ratio was90/9/1). D. vulgaris was cultured for 2 days prior to experiment in SRB2 media (Intertek). From this culture, 2 ml of inoculum was added to 18ml anaerobic phosphate buffered saline (PBS).

CuI with NaI and PVP was tested at concentrations of 60 and 10 ppmcopper (wt % Cu). CuI particles solutions were diluted in the inoculatedPBS media to the above concentrations to produce vials with 20 mlsolution. Each concentration was tested in duplicate. In addition, apositive control sample consisting of inoculated PBS without CuI wasalso tested. The sealed bottles were incubated at room temperature (23°C.) without agitation.

An initial sample was taken from the positive control to establish astarting concentration of bacteria for the experiment. 0.5 ml sampleswere taken at 1 hour time point and diluted in 4.5 ml anaerobicDey/Engely (D/E) neutralizing broth to neutralize the Cu bacteriocide. A1:10 dilution series was made using anaerobic PBS. Bacterial numberswere quantified by a 3-tube most probable number (MPN) method. Threetubes of anaerobic modified Baar's media (10 ml each) per dilution wereinoculated with 1 ml each from their respective diluted sample. Thesetubes were incubated at 37° C. for 72 hours. Positive samples wereevaluated based on the presence of iron sulfide (FeS), which forms ablack precipitate as a byproduct of hydrogen sulfide produced bybacterial growth reacting with iron included in the modified Baar'smedia.

All test media (PBS, D/E and modified Baar's media) were pretreated with100 μl Oxyrase oxygen scavengers (obtained from Oxyrase Inc, Mansfield,Ohio) to render the test media anaerobic. In addition, 100 μl of 3%cysteine were added to each bottle of modified Baar's media to furtherreduce oxygen contamination.

The starting concentration of the microbe in the experiment was 2.4×10⁴mpn/ml. At one hour time point the log₁₀ reduction (mpn/ml) using 60 ppmCu (as CuI) was greater than 3.90, for 10 ppm Cu it was greater than3.84 and for control it showed no reduction.

In another experiment the starting concentration of the microbe was2×10⁷ mpn/ml and series of dilutions were made with the lowest at 10³mpn/ml, and also SRB2 media was used instead of Barr's media. Theseresults compared with functionalized particles of CuI (same as above,i.e., with PVP and NaI) to a solution of CuCl₂ (Cu⁺⁺) and also withgluteraldehyde solution—a material commonly used as a biocide inpetroleum industry. The copper concentration in the first twoformulations was 10 ppm, and the gluteraldehyde concentration in thesolution was 10 ppm. The results after one hour of contact time showedthat the log₁₀ reduction for CuI was greater than 5.4, forgluteraldehyde this was greater than 4.23 and for CuCl₂ it was noteffective at any of the dilutions which were evaluated, and the onlyinference that could be made was that this reduction if any, must beless than 3.

In summary, this invention embodies antimicrobial compositions whichcomprise particles of low water solubility copper salts, wherein thesolubility is lower than about 100 mg/liter of water at roomtemperature. These particles are surface functionalized and theparticles are preferably less than about 1,000 nm in size. Theseparticles may constitute preferably 51% or more of low solubility coppersalts by weight and more preferably 71% or more by weight. In additionit is preferred that the functionalization agents should have amolecular weight of at least 60. Some preferred examples of low watersolubility copper salts are cuprous halides (e.g., chlorides, bromidesand iodides), cuprous thiocyanate and cuprous oxide and a most preferredsalt is cuprous iodide. A further advantage of cuprous iodide is that itis colorless or is faintly colored, which helps in avoiding strongcoloration to the products in which it is incorporated. In someapplications, the functionalized particles of low solubility coppersalts may be combined with other antimicrobial agents.

One may also use porous particles where copper or silver salts of lowwater solubility and other antimicrobial salts are incorporated therein.This incorporation or deposition of such salts is not done by exchangingions (ion-exchange) form the matrix of the porous particles. Suchparticles may also be used to make antimicrobial compositions.

In addition to the functionalized particles of copper salts and porousparticles containing antimicrobial salts, the antimicrobial compositionsof this invention may also comprise salts of high water solubility(typically with solubility in excess of 1 g/liter at room temperature).One may also incorporate organic acids, their salts and esters in thesecompostions as functionalization agents, or as additives to compositionswhere functionalization has been carried out using other materials.Preferred examples of high water solubility salts are alkali halides,such as iodides of lithium, sodium and potassium. Preferred examples oforganic acids and their salts are ascorbic acid, citric acid, cinnamonicacid, alkali ascorbate, alkali citrate and alkali cinnamonate.

Examples of preferred functionalization agents are ascorbic acid, citricacid, cinnamonic acid, alkali ascorbate, aminoacids, alkali citrate andalkali cinnamonate anionic surfactants, polyvinylpyrrolidone, chitosan,polyethyleneglycol, carboxymethylcellulose, polyacrylamide, andcopolymers comprising at least one of an anionic polymer,polyvinylpyrrolidone, polyolefin, polyvinyl acetate and polyethyleneoxide.

The functionalized particles of this invention can be made veryeconomically by wet grinding in the presence of functionalizing agents.Such methods may be used to produce functionalized particles of avariety of materials, including silver salts.

These antimicrobial compositions may be used against a variety ofmicrobes including Gram-positive bacteria, Gram-negative bacteria,viruses, fungi, mycobacteria, aerobic and anaerobic bacteria. Thesecompositions may be used in a large number of applications where theyare added to liquid or solid carriers to impart antimicrobial propertiesto the products containing such particles. Solid coatings are consideredas examples of solid carriers or solid products and coating formulationsare considered as an example of liquid carriers or liquid products.Examples of some applications are products for disinfectants, coatings,personal care, wound care, waste processing and petroleum extraction.

It will be understood that various modifications may be made to theembodiments disclosed herein. Hence the above description should not beconstrued as limiting, but merely as exemplifications of preferredembodiments. Those skilled in the art will envision other modificationsthat come within the scope and spirit of the claims appended hereto. Allpatent applications cited as priority (related applications) areexplicitly incorporated herein by reference in their entirety.

1. An antimicrobial article of manufacture comprising particles ofcopper iodide in a size less than 1,000 nm present in said article at aconcentration of less than about 5% by weight.
 2. The antimicrobialarticle of manufacture in claim 1, being a liquid suspension.
 3. Theantimicrobial article of manufacture in claim 1, where the said articleof manufacture is selected from at least one of a coating, moldedproduct, extruded product, tubular product, fiber product, film productand an adhesive product.
 4. The antimicrobial article of manufacture inclaim 1, further comprising one or more agents with reducing properties.5. The antimicrobial article of manufacture in claim 4 wherein the saidagents are selected from at least one of (a) organic acids and mineralacids; (b) salts and esters of organic acids; and (c) alcohols,aldehydes and polyols.
 6. The antimicrobial article of manufacture inclaim 4, where the said agents are selected from acetic acid, ascorbicacid, citric acid, glutamic acid, sorbic acid, erythorbic acid,thiodipropionic acid, sulfamic acid, adipic acid, gallic acid, alginicacid, caprylic acid, linoleic acid, cinammic acid, alkylbenzene sulfonicacids, ascorbates, citrates, carbohydrates, sugars, glucose, xylitol,sorbose, cinnamonaldehyde, lauryl gallate and ascorbic acid palmitate.7. The antimicrobial article of manufacture in claim 1, furthercomprising at least one of (a) a water soluble salt and (b) anotherantimicrobial material.
 8. The antimicrobial article of manufacture inclaim 1, further comprising at least one agent which assists inpreventing oxidation of cuprous ions, wherein the said agent is selectedfrom at least one of organic acids including acetic acid, ascorbic acid,citric acid, glutamic acid, sorbic acid, erythorbic acid,thiodipropionic acid, sulfamic acid, adipic acid, gallic acid, alginicacid, caprylic acid, linoleic acid, cinammic acid and alkylbenzenesulfonic acid; polyols and carbohydrates including sugars, glucose,xylitol and sorbose; aldehydes; salts of organic acids and esters oforganic acids.
 9. The article of manufacture in claim 1, furthercomprising at least one of (a) a water soluble salt and (b) anotherantimicrobial material.
 10. An antimicrobial article of manufacturewhich contains particles in a concentration of less than about 5% byweight of at least one cuprous salt wherein the said salt has a roomtemperature water solubility of less than 100 mg/liter and theantimicrobial article of manufacture further comprises a reducing agent.11. The antimicrobial article of manufacture in claim 10, being a liquidsuspensiond.
 12. The antimicrobial article of manufacture in claim 10,being a solid or a coating.
 13. The antimicrobial article of manufacturein claim 10, being a solid that is a solid article of manufacturecomprising at least one of a thermoplastic or a thermoset polymer. 14.The antimicrobial article of manufacture in claim 13, where the saidsolid article of manufacture is selected from at least one of a moldedproduct, extruded product, tubular product, fiber product, film productand an adhesive product.
 15. The antimicrobial article of manufacture inclaim 10, further comprising at least one of (a) a water soluble saltand (b) another antimicrobial material.
 16. An antimicrobial article ofmanufacture which contains particles in a concentration of less thanabout 5% by weight of at least one copper salt, wherein the said salthas a room temperature water solubility of less than 100 mg/liter andthe surfaces of said particles are modified by at least onefunctionalizing agent with a molecular weight of at least
 60. 17. Theantimicrobial article of manufacture in claim 16, being a liquidsuspension.
 18. The antimicrobial article of manufacture in claim 16,being a solid or a coating.
 19. The antimicrobial article of manufacturein claim 16, further comprising an agent with reducing properties. 20.The article of manufacture in claim 16, wherein the said copper salt isselected from the group consisting of cuprous oxide, cuprousthiocyanate, CuI, CuBr and CuCl.